PB97-916501

NTSB/PAR-97/0l

NATIONAL

TRANSPORTATION

SAFETY

BOARD

WASHINGTON, D.C. 20594

PIPELINE ACCIDENT REPORT

SAN JUAN GAS COMPANY, INC./ENRON CORP.

PROPANE GAS EXPLOSION IN SAN JUAN, PUERTO

RICO, ON NOVEMBER 21, 1996

6789C
Abstract: About 8:30 a.m. on November 21, 1996, because of a propane gas leak, a

commercial building in San Juan, Puerto Rico, exploded. Thirty-three people were killed, and at

least 69 were injured.

The safety issues discussed in this report are the adequacy of employee training, the need

for an excavation-damage prevention program, the adequacy of maps and records of buried

facilities, the adequacy of public education on what to do when the odor of gas is detected, and

the adequacy of the oversight of the San Juan Gas Company, Inc., from Enron Corp., the Puerto

Rico Public Service Commission, and the Office of Pipeline Safety.

As a result of its investigation, the National Transportation Safety Board issued

recommendations to the Secretary of the U.S. Department of Transportation, the Research and

Special Services Administration, the Puerto Rico Public Service Commission, Enron Corp., and

Heath Consultants, Inc.

The National Transportation Safety Board is an independent Federal agency dedicated to

promoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Established

in 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 to

investigate transportation accidents, determine the probable causes of the accidents, issue safety

recommendations, study transportation safety issues, and evaluate the safety effectiveness of

government agencies involved in transportation. The Safety Board makes public its actions and

decisions through accident reports, safety studies, special investigation reports, safety

recommendations, and statistical reviews.

Information about available publications may be obtained by contacting:

National Transportation Safety Board

Public Inquiries Section, RE-51

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594

(202) 314-6551

Safety Board publications may be purchased, by individual copy or by subscription, from:

National Technical Information Service

5285 Port Royal Road

Springfield, Virginia 22161

(703) 605-6000
	

		

			
	

	
		



PIPELINE ACCIDENT REPORT

Adopted: December 23, 1997

Notation 6789C



	




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iii

CONTENTS

EXECUTIVE SUMMARY...........................................................................................................vii

INVESTIGATION .......................................................................................................................... 1

The Accident ................................................................................................................................... 1

Week Preceding Accident........................................................................................................ 1

Thursday, November 14........................................................................................................... 3

Friday, November 15................................................................................................................ 3

Monday, November 18............................................................................................................. 5

Wednesday, November 20 ....................................................................................................... 5

Thursday, November 21........................................................................................................... 7

Injuries............................................................................................................................................. 9

Emergency Response....................................................................................................................... 9

Survival Aspects............................................................................................................................ 11

Damage.......................................................................................................................................... 11

Personnel Information ................................................................................................................... 12

Dispatcher. ............................................................................................................................. 12

Technician.............................................................................................................................. 12

First Brigade Leader............................................................................................................... 12

Second Brigade Leader .......................................................................................................... 12

Third Brigade Leader ............................................................................................................. 12

MCC....................................................................................................................................... 13

Assistant Operations Superintendent ..................................................................................... 13

Operations Superintendent..................................................................................................... 13

Safety Manager ...................................................................................................................... 13

General Manager.................................................................................................................... 14

Fatigue.................................................................................................................................... 14

Training ......................................................................................................................................... 14

SJGC Training........................................................................................................................ 14

Leak Survey Training............................................................................................................. 15

Gas Company Operations.............................................................................................................. 16

Gas Distribution and Ownership............................................................................................ 16

Pipes and Ducts Installed on Camelia Soto............................................................................ 16

Public Education .................................................................................................................... 17

Emergency Procedures........................................................................................................... 18

Leak Surveys.......................................................................................................................... 19

Odorization............................................................................................................................. 19

Excavation-Damage Prevention Program .............................................................................. 20

Gas Maps and Records........................................................................................................... 20

Corrosion Protection. ............................................................................................................. 21

Plastic Pipe............................................................................................................................. 21

Abandoned Services............................................................................................................... 22
iv

Unaccounted for Gas.............................................................................................................. 22

Meteorological Information .......................................................................................................... 22

Medical and Pathological Information .......................................................................................... 22

Tests and Research ........................................................................................................................ 23

SJGC Pipelines....................................................................................................................... 23

Sbarro Restaurant Propane Fuel Lines................................................................................... 25

Smoke Migration Tests .......................................................................................................... 25

Examination of Debris and Retrieved Damaged Materials.................................................... 27

Laboratory Examination of Failed Pipes................................................................................ 28

Oversight and Regulation.............................................................................................................. 29

Enron...................................................................................................................................... 29

PSC ........................................................................................................................................ 32

PSC Inspections of SJGC ............................................................................................... 32

PSC Annual Program Certification................................................................................. 34

OPS ........................................................................................................................................ 35

Other Information.......................................................................................................................... 36

Humberto Vidal...................................................................................................................... 36

Emergency-Response Procedures ................................................................................... 36

HV Building.................................................................................................................... 36

Excavation-Damage Prevention............................................................................................. 36

ANALYSIS ................................................................................................................................... 38

Exclusions ..................................................................................................................................... 38

The Accident ................................................................................................................................. 39

Propane Release Points .......................................................................................................... 39

Migration Paths into HV Basement. ...................................................................................... 39

Fueling the Explosion. ........................................................................................................... 39

Location of Explosion in HV Building. ................................................................................. 40

Gas Leak Investigation Procedures ............................................................................................... 40

Excavation-Damage Prevention.................................................................................................... 40

Emergency Response..................................................................................................................... 44

Survival Aspects............................................................................................................................ 44

Public Education ........................................................................................................................... 46

Employee Training........................................................................................................................ 49

Assessing Effectiveness of Training on Barhole Depth......................................................... 50

Federal Employee Training Requirements............................................................................. 52

Pipeline Safety Oversight.............................................................................................................. 53

Enron...................................................................................................................................... 54

PSC ........................................................................................................................................ 54

OPS Oversight of State Pipeline Safety Program .................................................................. 56

CONCLUSIONS........................................................................................................................... 58

Findings......................................................................................................................................... 58

Probable Cause.............................................................................................................................. 59
v

RECOMMENDATIONS .............................................................................................................. 60

APPENDIX A: Investigation and Hearing.................................................................................... 63

APPENDIX B: Summary of PSC Compliance Inspections of SJGC ........................................... 65

APPENDIX C: Summary of OPS Oversight Actions Relative to PSC ........................................ 69

APPENDIX D: Employee Training and Qualifications................................................................ 77

APPENDIX E: Sketch of Basement Showing Direction of Forces on Columns.......................... 79

ABBREVIATIONS....................................................................................................................... 83

vii

About 8:30 a.m. on November 21, 1996,

because of a propane gas leak, a commercial

building in San Juan, Puerto Rico, exploded.

Thirty-three people were killed, and at least 69

were injured.

The building was in Rió Piedras, a shopping

district in San Juan. The structure was a sixstory mixture of offices and stores owned by

Humberto Vidal, Inc. The company’s

administrative offices occupied the third, fourth,

fifth, and sixth floors, and the first and second

floors housed a jewelry store, a record store, and

a shoe store.

The National Transportation Safety Board

determines that the probable cause of the

propane gas explosion, fueled by an excavationcaused gas leak, in the basement of the

Humberto Vidal, Inc., office building was the

failure of San Juan Gas Company, Inc., (1) to

oversee its employees’ actions to ensure timely

identification and correction of unsafe

conditions and strict adherence to operating

practices and (2) to provide adequate training to

employees. Also contributing to the explosion

was (1) the failure of the Research and Special

Programs Administration/Office of Pipeline

Safety to oversee effectively the pipeline safety

program in Puerto Rico, (2) the failure of the

Puerto Rico Public Service Commission to

require San Juan Gas Company, Inc., to correct

identified safety deficiencies, and (3) the failure

of Enron Corp. to oversee adequately the

operation of San Juan Gas Company, Inc.

Contributing to the loss of life was the

failure of San Juan Gas Company, Inc., to

inform adequately citizens and businesses of the

dangers of propane gas and the safety steps to

take when a gas leak is suspected or detected.

In its investigation of this accident, the

Safety Board addressed the following safety

issues:

• Adequacy of employee training.

• Need for an excavation-damage prevention

program.

• Adequacy of maps and records of buried

facilities.

• Adequacy of public education on what to do

when the odor of gas is detected.

• Adequacy of the oversight of the San Juan

Gas Company, Inc., from Enron Corp., the

Puerto Rico Public Service Commission,

and the Office of Pipeline Safety.

As a result of its investigation, the Safety

Board issues one safety recommendation to the

Secretary of the U.S. Department of

Transportation, three to the Research and

Special Programs Administration, two to the

Puerto Rico Public Service Commission, two to

Enron Corp., and one to Heath Consultants, Inc.

EXECUTIVE SUMMARY

1

The Accident

About 8:30 a.m. on November 21, 1996,

because of a propane gas pipeline leak, a

commercial building in San Juan, Puerto Rico,

exploded. Thirty-three people were killed, and

at least 69 were injured.

The building was in Rió Piedras, a shopping

district in San Juan. (See figure 1.) The structure

was a six-story mixture of offices and stores.

Humberto Vidal, Inc., (Humberto Vidal) had

bought the building (the HV building) in 1984,

and the company’s administrative offices

occupied the third, fourth, fifth, and sixth floors.

The first and second floors of the building

housed a jewelry store, a record store, and a

shoe store.

The building was on the corner of José de

Diego and Camelia Soto. (See figure 2.) The

San Juan Gas Company (SJGC)1

 was the local

gas pipeline distribution company. The company

had a 4-inch cast-iron gas main on de Diego. A

2-inch abandoned gas line, a pressurized steel

service pipe, ran from the main to the HV

building, about 6 to 8 inches east of the east

wall. The service pipe did not enter the building,

and gas had not been used in the building for

more than 10 years.

The Humberto Vidal Shoe Store was on the

first floor, and its front door was on de Diego.

The store was owned by Humberto Vidal, which

owned other shoe stores in Puerto Rico, as well.

Week Preceding Accident.--Many people

later reported that they had detected the odor of

gas inside buildings and along streets adjacent

to the HV building for at least a week before the

explosion.

Several HV employees had worked in the

basement and on the first floor early in the

 

1

San Juan Gas Company, Inc., is a corporation that is wholly

owned by Enron Corp. Unless otherwise indicated, the use in this

report of “the SJGC” refers to the current Puerto Rico Corporation

or to any of its predecessor names.

mornings before the air conditioning was

started. They had smelled a strong odor that they

identified as propane gas. Those who had

worked in the basement complained of

dizziness, nausea, and difficulty breathing while

in the basement. One HV employee stated that

most of the HV employees had smelled the gas

odor, as did some customers. She said the odor

was strongest in the basement, where

merchandise was stored. The manager of the shoe

store (who later died in the explosion) told her

that he had advised one of the HV officials that

employees could not go into the basement

because of the strong smell of propane gas.

INVESTIGATION

  	
 



	

 
 

 

 
 






 

   
   





 
 

   





   


  

 




   


 
  


 


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Figure 1. Accident Location Map.

Some of the employees at the Chicken

Kingdom had told their supervisor that they had

smelled a strong odor of gas that came and went.

The supervisor stated that he called the company

that serviced his gas cooking equipment and had

all of the equipment tested. No leaks were

found. He stated that the equipment-company

personnel assumed that the odor must be

associated with gas work going on along

Camelia Soto, since someone was constantly

there checking for gas leaks.

The administrator of the Chicken Kingdom

stated that he used a pay telephone to report to

the SJGC that his employees had smelled gas.

The SJGC employee receiving the call asked for

the street name. The administrator explained to

him that the smell came and went. The SJGC

employee said the gas company would take care

of the problem. The administrator stated that the

SJGC employee did not ask for his name, for his

company’s name, whether the smell was inside

or outside, or any other questions. The

administrator also said that the SJGC employee

did not tell him what actions he should take.

After he made the report, the administrator said,

he saw an SJGC truck and SJGC employees

working in the area and assumed that they had

come in response to his call. He stated that he

never smelled gas in the area while he was

outside his building. He also said that during the

week or so before the explosion, he had been in

Joyería Super Precio, Disco Fiesta, and La

California stores and had not detected the odor

of gas.
3

The owner of Pepe Ganga stated that some

of his employees had commented to him before

the explosion about detecting an odor in the

store that they thought might be propane gas. He

said that he thought that the odor might have

come from the exhaust fumes of the local bus or

other vehicles using the street.

Thursday, November 14.--According to the

SJGC, the first report it received of the odor was

on Thursday, November 14. The SJGC

dispatcher on duty that morning said that the

manager of the shoe store telephoned him at

8:15 a.m.2,3 The dispatcher said the manager told

him that he smelled gas when he opened the

store and that when he went into the basement,

he could smell gas, although the odor was not

very strong. The dispatcher stated that he

recorded the call and told the manager what he

told anyone who reported smelling gas--leave

the basement door open and try not to turn on

any electrical appliances or anything that has to

do with electricity.

The dispatcher sent a technician to

investigate. The technician arrived at the shoe

store about 9:30 a.m. and met with a store

employee, probably the store manager. The two

then walked down the basement stairs, which

were on the east side of the building (the side

next to La California). They walked to the north

wall of the building (the wall along de Diego),

where the manger pointed to the upper right part

of the wall and said that the odor seemed to be

coming from there. He told the technician that

he smelled gas in the mornings when he entered

the store. The technician had a gas detector with

him, the kind that is not accurate unless it is

turned on in an area that is free of gas. Once

turned on and moved to an area that is suspected

of containing gas, the detector will beep if it

detects gas. The technician did not turn the

detector on until he had been in the store for

 

2

According to computer records of Telefonica de Puerto

Rico, telephone calls were made to the SJGC on November 14,

1996, from the HV building phone normally used by the manager

at both 7:43 and 8:22 a.m. The duration of the first call was 83

seconds; the second call lasted for 5 minutes and 17 seconds.

3

At this time and until after the explosion, it was the

dispatcher’s practice to not record leak calls from the same address

made after one for which a work order had already been issued.

The dispatcher did not acknowledge that two calls were received

from the HV shoe store on the morning of November 14, 1996.

about 5 to 10 minutes. When he used it to test

the basement air, the detector did not beep.

According to the SJGC dispatcher, the

technician spoke with him from the HV building

and said that he smelled a slight odor of gas out

on the street, but not in the basement.

Friday, November 15.--On Friday,

November 15, the SJGC sent a brigade to the

building. The brigade, consisting of four men

and a leader, arrived at 8:15 a.m. The leader had

been told by his supervisor that the store

manager was complaining of an odor of propane

gas inside the building. When the brigade

arrived, the store manager told the leader that he

smelled propane gas in the store, and both men

entered the basement by the stairs at the east

wall. In the basement, they walked about 12 to

15 feet north from the stairs, and the manager

told the leader that they had reached the spot

where he had smelled gas and that the odor

seemed to be coming down from the basement

ceiling. According to the leader, both he and the

manager agreed that they could not smell gas at

that time. The leader later stated that the

manager had told him that sometimes in the

morning when he opened the store he could

smell gas. The leader did not have an instrument

with him for testing the basement atmosphere

for the presence of gas, so he went outside to

test the underground with a combustible gas

indicator (CGI).

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The brigade made about 18 to 20 barholes4

about 4 feet apart in de Diego and, according to

the leader, about 18 to 20 inches deep or deeper.

They began east of La California and proceeded

west. The leader said that the CGI read 0 until it

was about 2 to 3 feet beyond the east wall of the

HV building. In a barhole about 4 feet west, the

CGI indicated about 2 to 3 percent on the lower

explosive limit (LEL) scale.5

 As the leader

pumped the CGI to draw in more air from the

barhole, the CGI reading dropped.6

 He repeated

the test several times, and each time he obtained

the same result.

The brigade continued its survey until it was

within 20 to 30 feet of Camelia Soto, and the

CGI continued to read 0. The leader called the

gas company to find out whether any gas pipes

went from the main to the HV building. The

company told him about the old line that ran

from the main into the building. The brigade

excavated the area over the old line, located it,

disconnected it from the main, and plugged the

opening of the main. The leader stated that a

laborer plugged the open end of the old line.

(Inspection after the explosion found that the

gas service pipe had not been plugged.)

According to the leader, the brigade

members used a soap solution to test for leaks in

the part of the main they had uncovered. They

detected no leaks, so they reburied the main and

compacted the soil over and around it. The

brigade leader stated that he told the manager to

call the SJGC if he again smelled gas.

Monday, November 18.--On Monday

morning, November 18, an HV employee told

the manager that the odor of gas in the shoe

store was very strong. The manager told her that

he had already spoken with the SJGC and that

the company was not paying much attention.

 

4

A barhole is a hole that is made in the soil or paving for the

specific purpose of testing the subsurface atmosphere for the

existence of a combustible gas.

5

The LEL is the lowest concentration in air of a flammable

gas that can be ignited.

6

Once a combustible gas is detected, the person operating the

CGI draws additional samples from the barhole to see if the CGI

reading can be reduced. A reduction in the CGI reading indicates

that the combustible gas is flowing into the barhole at a rate less

than the sampling rate.

She later stated that he asked her to go to the

basement with him and that she walked from the

staircase about halfway to the north wall, but

could not go any farther because the odor was

strong enough to make her dizzy and nauseated.

She had to go back upstairs to get some air.

The following day, November 19, was a

holiday, and the shoe store was closed.

Wednesday, November 20.--The employee

who had gone into the basement on Monday

said that on Wednesday, November 20, the odor

was still present and the smell appeared to be

about the same. She stated that she did not go

into the basement again because she was afraid.

According to the SJGC dispatcher, an

unidentified person (believed to be the store

manager) called from the HV building a short

time before 8 a.m. and said that a slight odor of

gas was detectable in the building. The

dispatcher did not record the call. The

dispatcher stated that he used the November 14

work order to dispatch a brigade because “they

keep on calling.” He said that, as before, he

advised the caller that the building should be left

open.

The dispatcher said that later in the morning

a woman called to report an odor of gas in the

building, but he did not take her name since the

company had already dispatched a brigade.

(According to the SJGC’s records, the only

other call the SJGC received that day from the

HV building was in the early afternoon.) Later

that morning, when the store manager saw an

HV official who worked in the building, he told

the official about the odor. The official told the

manager to open the door or get some fans if the

smell got worse, as he did not want customers to

smell the gas. Reportedly, the manager did not

follow the instructions because it would have

been difficult for him to watch the merchandise

if the door were open.

After the accident, the SJGC operations

superintendent, the supervisor of the dispatcher,

stated that he recalled the dispatcher telling him

on November 20 about receiving a complaint

from the store manager. The operations

superintendent said that he responded to the

complaint by dispatching a brigade leader and a

five-person crew to investigate. He instructed

them to go into the store and store basement and
6

to probe the street outside the store to make

certain that there were no problems inside the

building. He stated that he instructed the brigade

leader to take all the time needed to investigate

the report because the brigade leader who went

to the building on November 15 had not gone all

the way into the basement.

The leader of the November 20 brigade

stated that he understood that he was responding

to a call reporting a strong odor of gas in the

store. He was aware that other SJGC employees

had previously responded to a similar complaint

and that they had made some barholes. He said

that when he arrived at the store, he talked to the

manager, who, he claimed, said that he was not

sure that what they were smelling in the

basement was gas, but that his employees were

telling him that it was gas. The leader said that

he went throughout the basement with the

manager checking for any gas pipe or odor of

gas; he said he found neither. He did not use an

instrument to check for gas, but he smelled a

strong odor, which he believed to be the odor of

rubber. He said that when he smelled what he

believed to be rubber, HV employees were

unpacking shoes, readying them to be put on

shelves.

According to two HV employees, no one

worked in the basement on November 20

because the odor of gas was too strong.

Merchandise arriving at the store that day was

stored on the first floor instead of in the

basement. One of the two employees reported

entering the basement to look for merchandise

requested by customers. She said that she tried

holding her breath because of the odor. She

estimated that she was in the basement about 5

minutes and became dizzy and nauseated. The

other reported that he was unable to fully enter

the basement because the “fumes” were too

strong.

Another HV employee, a messenger, said

that he had walked with the store manager and

the leader to the stairs. The messenger said that

although he did not go into the basement, he

became nauseated from the gas odor, as did

another employee. The messenger stated that he

stayed at the top of the stairs because the gas

odor was too strong, but that the leader and the

manager walked about halfway down the stairs.

The messenger said that the two men did not go

completely into the basement and that he

overheard the leader say that it smelled like gas.

Propane gas is heavier than air. The leader

stated that he knew that propane gas tends to

pool and not to rise when it is released

underground and that it is therefore necessary to

probe deeper into the soil because pockets of

propane may be below the gas main. A few days

after the explosion, the leader said the barholes

his brigade had made were about 12 to 18 inches

deep. He said that he did not verify the depth of

the holes except by comparing their depth to the

length of the probe for his CGI. He estimated

the probe was 2 feet long.

In January 1997, the leader said that he

made new barholes rather than using the old

ones because he recalled being instructed never

to use old holes because water might have

collected in them, which could damage the CGI.

He claimed that he had observed the barholes to

be about 2 to 2 1/2 feet deep and was aware that

the gas main was 2 feet deep. He said that,

beginning at the intersection of Camelia Soto

and de Diego, on the west side of the building,

his brigade made barholes, first at 20-foot

intervals and then at 10-foot intervals, to the

east until they were about 15 to 20 feet from

Monseñor Torres. He said he had had two

reasons for thinking that he knew where the gas

main on de Diego was: he had had previous

experience with it; another brigade had marked

the location of the gas main with crayon when it

was repairing the service line to La Milagrosa

School.

The brigade made barholes at 10-foot

intervals along both sides of Camelia Soto. (The

barholes on the eastern side of Camelia Soto

started about 5 feet south of the Chicken

Kingdom and continued to de Diego. The

barholes on the western side of Camelia Soto

began at the Comerical Ubiñas gas service line

and continued to de Diego.) The leader said he

had decided on making barholes along Camelia

Soto because he thought there was a gas main

on Camelia Soto and that he had thought that

gas might have migrated from the main on

Arzuaga or the main on Camelia Soto to de

Diego. (De Diego is downhill from Arzuaga.)

He said that the crew found no indications of

combustible gas in any of the holes they made

that morning.
7

The leader said that had he known there was

a gas service to the Chicken Kingdom, he would

have probed over that line also. He said that he

knew that a service line ran to the Comerical

Ubiñas building because he could see the meter,

but he was not aware that a service line ran to

the Chicken Kingdom. He did not call the

dispatcher to learn the locations of gas pipes in

the area, nor did he use a pipe locator, the maps

in his truck, or other means to locate the gas

lines.

The SJGC operations superintendent later

testified that on November 20, the leader

reported that he had found a power transformer

that was leaking oil in the basement of the HV

building. (The leader did not report this

information when interviewed by a Safety Board

investigator, nor was there a transformer in the

basement.) The operations superintendent stated

that the leader told him that his crew had used a

soap-and-water solution to test the location

where a gas service had once entered the

building (the leader testified that he looked for

evidence of gas lines entering the basement and

found none) and at other locations, but found no

areas indicating the entry of propane gas.

The leader said that his CGI had been used

by others the previous day and around noon he

wondered whether it was operating correctly,

since he had not found any indication of

combustible gas in the barholes. He and the rest

of the brigade drove to the SJGC shop, where

they had the CGI tested. It was found to be

functioning properly.

Meanwhile, the HV messenger told the HV

attorney that the gas odor was still in the basement and, at times, the odor could be detected in

the stores in the building. According to the

attorney, she called the SJGC after 1 p.m. and

reported what the messenger had told her. On

receiving her complaint, the SJGC dispatcher

informed the operations superintendent. He

radioed the leader, who was in the shop testing

the CGI, and told him to return to the HV

building to check again for gas leaks. He stated

that he instructed the leader to test in all

directions for leaks and to test even further from

the building because he wanted to know why the

HV employees were calling.

The leader and the rest of the brigade

returned to the HV building and re-tested all of

the holes that had been made that morning.

Again, they did not detect combustible gas.

About 5 p.m., the brigade returned to the SJGC

shop. The brigade leader talked with the

maintenance and construction coordinator

(MCC) and reported that his testing had not

revealed evidence of combustible gas near the

HV building. He also advised that a store

employee had reported detecting the odor of gas

that morning when the store was first opened.

The MCC stated that he did not believe that

there was a gas leak at the HV building because

he knew the results obtained by previous crews

and because he trusted his personnel and the

instruments that they used.

Thursday, November 21.--On November

21 about 6:45 a.m., air conditioning contractors

(a father-and-son team) arrived to do the routine,

monthly maintenance on the air conditioners

that they had been doing for the past 10 years.

They met the store manager and the messenger

outside. According to the messenger, the

manager opened the door to the store and said

that he smelled gas. The messenger said his

stomach became upset and he told the manager

to call the SJGC because the odor was so strong.

The manager turned on the lights, and the four

men entered the building together. The manager

and the contractors walked through the store to

the elevator on the west side of the building.

The son (the father died in the accident) later

stated that when he entered the building, he did

not detect any unusual odors but said the

manager told him about detecting a strong odor

of gas. The three used the elevator to go to the

building receptionist area on the fourth floor,

where the manager opened the office doors and

left.

According to the son, the building air

conditioners usually were not turned on until 8

a.m. or later. It was usual for the store manager

to turn on all the air conditioning units at their

control panels; however, the son stated that

when he worked on the basement air

conditioner, he would turn the unit on and off as

needed. To perform their work, the contractors

would feel the air conditioner pipes after the air

conditioner had run for a while to assess

whether the machine was working properly, and
8

as needed, they would wash the compressor and

filters.

An employee who arrived at work between

about 7 and 7:10 a.m. said that as she entered

the building, she smelled the odor of gas, an

odor that had been present for the past week and

a half. She said the odor was strong enough that

it “went over the top of the regular odor [shoes]

of the store.” She recognized the odor as

propane gas because she had a propane gas

stove at home. As she did most mornings during

this period, she mentioned the odor to the store

manager. He told her that he would call the gas

company again that morning

 and that he was

continuing to keep a log of his calls. (His call

log was not found after the explosion.) The store

manager’s brother entered the store, and the

three of them were together until 8 or 8:05 a.m.,

when the employee left the building to get

breakfast.

The manager’s brother stated that when he

entered the building, he smelled propane gas.

The manager complained to him about the

strong odor of gas and told him that he had

become dizzy and nauseated. The manager

asked him to go into the basement to check on

the odor. The brother walked to the bottom of

the basement stairs, sniffed the air, and would

go no farther because his eyes became irritated

and he could not stand the smell. He ran back

upstairs, advised the manager to leave the

building, and soon left himself.

The son from the air conditioning contractor

team said that he completed his work on the

third and fourth floors about 7:50 and left the

building. He stated that his father began

working on the fifth floor and was to work all

floors other than the third and fourth. The son

said that he was aware of the odor produced by

the shoes stored in the building and of the smell

of propane gas from the pipe system. He stated

that he did not detect the odor of gas that day in

the areas he visited.

In the meantime, the MCC had decided to

send a third brigade, which he dispatched at 7.

The workmen arrived about 7:30 and parked

 

7

Telephone records on calls from the HV building do not

show a call having been made to the SJGC that morning.

their truck on de Diego, in front of the building.

The MCC said he sent the brigade to make sure

there was no gas in the building and to learn

what the HV employees were smelling when

they opened the building.

The brigade leader reported that he was

given no instructions on contacts to be made at

the building and that he had not been told that

there had been previous complaints or what the

previous SJGC crews had done. He said that

because he was not told of the previous actions,

he did not take with him any plans or other

information about the gas piping in the area. He

knew that there was suppose to be a map of the

gas mains in the truck, but he did not consider

the map important because he knew he could

use his radio to obtain any information he

needed.

The leader said that he did not smell gas on

the outside of the building when he arrived and

that he did not see anyone at the store door. He

believed the store had not yet opened because

the outside roll-up door was halfway up and the

inside door was closed.8

 At no time did he or his

brigade members meet with or talk to any HV

employee. Without referring to the gas main

map in the truck, he went to the barholes he saw

in de Diego, beginning in front of the entrance

to the HV building and extending west to the

intersection of de Diego and Camelia Soto. He

believed that the barholes had been made the

previous day by another brigade. He stated that

the holes were about 18 inches deep and about 6

feet north of the curb. He believed their

locations to be over the gas main because he

recalled the location of the gas main from an

earlier time when he saw it exposed to

reestablish gas service to the school across from

the HV building. He inserted his CGI probe into

the holes and tested in each. He detected no

odor of gas, and his CGI did not register any

indication of a combustible gas.

The administrator of the Chicken Kingdom

stated that as he drove past the HV building on

his way to work, he saw the SJGC brigade

 

8

The outside door was a solid metal roll-up door that was

about 30 feet wide and covered the store entrance and the glass

display windows. The inside door was a metal mesh roll-up door

located further from de Diego than the outside door, and it was

located across the approximately 6-foot wide store entrance.
9

working in the area. He said that about a half

hour before the explosion he detected a “little”

gas odor in the store when the breeze blew into

the store.

The leader had three new barholes made in

de Diego, between the jewelry store and the

manholes in the intersection of Camelia Soto

and de Diego. He said that the holes were 18

inches deep and about in line with the

previously made barholes that he had already

tested that morning. No combustible gas was

detected in the three new holes. Next he had the

crew make more barholes in the intersection of

Camelia Soto and de Diego. As soon as the

barholes were made, just before 8:30, he used

his CGI and obtained a reading of 20 percent on

the gas scale, but he detected no odor of gas.

About 5 to 10 seconds afterwards, while he was

standing on the manhole cover and another

employee was making another barhole, the

explosion occurred. The force lifted him into the

air and threw him about 15 to 20 feet to the

north.

People who were in the HV and adjacent

buildings sustained minor to serious injuries.

Those on the lower floors of the HV building

received the more serious injuries. The bodies of

the store manager and the air conditioning

service technician were later found in the

basement. Some people outside and near the HV

building were severely injured or killed by

debris propelled by the explosion. (See figure

3.)

Injuries

  "#$% & '$%%(

$

)
 *  

*'4 - 0 ++

5/6( - 1 7 ,-

/865 7 90 ..

868 7 /0

'6'4 ,0 . 11 //1

Title 49 Code of Federal Regulations (CFR)

830.2 defines a fatal injury as: any injury which

results in death within 30 days of the accident.

A serious injury is one that requires

hospitalization for more than 48 hours,

commencing within 7 days from the date the

injury was received; results in a fracture of any

bone (except simple fractures of fingers, toes, or

nose); causes severe hemorrhages, nerve,

muscle, or tendon damage; involves any internal

organ; or involves second-or third-degree burns,

or any burn affecting more than 5 percent of the

body surface.

Emergency Response

Immediately after the explosion, police

officers on Camelia Soto and Arzuaga ran

toward the building and began helping the

injured and those trapped on the upper floors.

Firefighters at the Rió Piedras fire station,

which was about 1⁄4-mile from the HV building,

heard the explosion and arrived in a pumper

truck about a minute later. They observed cars

turned upside down, injured and dead people in

the street, and devastated buildings, but no fire.

They radioed for assistance, and within minutes

additional fire, medical, and police personnel

and equipment arrived. Firefighters provided

first aid, removed bodies, and evaluated the

risks of entering the building. The Puerto Rico

Police dispatched members of its bomb squad to

investigate.

At 8:42, the police notified the trauma

center at the Rió Piedras Medical Center, which

initiated its disaster plan. A triage area was set

up at La Milagrosa School.

11

At 8:45, a San Juan Civil Defense

Department search and rescue worker, who had

been trained in handling gas emergencies, was

dispatched to the scene. When he arrived, he

smelled a strong odor of gas, but did not see any

evidence of fire or smoke. Dust was still coming

from the building, and he said he saw injured

and dead people all over the area. He said that

people were shouting and screaming and that

although he attempted to administer first aid,

many victims could not be reached because the

debris and objects falling from the HV building

made it dangerous to approach them. The streets

into the area were narrow and became congested

with arriving vehicles, hampering traffic flow

into and out of the area.

The Puerto Rico Secretary of Health was

notified of the accident at 8:50 and dispatched

medical teams and Mental Health Crisis

Counseling personnel. A medivac unit was

dispatched to transport patients as necessary.

The Disaster Preparedness Improvement

Director of the State Civil Defense arrived about

9:00, assumed the role of incident commander,

and coordinated the response efforts of

participating agencies. At 9:15, the San Juan

Civil Defense Department dispatched more

search and rescue people.

At 10:00, rescue groups entered the HV

building, and some areas of the structure began

to collapse. The rescue was discontinued until

the Department of Housing, which is

responsible for public safety related to the

damaged buildings, arranged for structural

engineers to assess the stability of the building.

By 12:30 p.m., the engineers had identified

those areas of the building believed to be stable

enough for the rescue workers to enter. The

Salvation Army and the American Red Cross

also responded and provided support services.

Representatives of the Federal Emergency

Management Agency (FEMA) and the Puerto

Rico Secretary of State, as Acting Governor,9

worked with the incident commander to

coordinate the response. At 2:30 p.m., the

Acting Governor requested a Presidential

 

9

The Secretary of State serves as Acting Governor at times

when the Governor is unavailable.

Declaration that the area in which the explosion

occurred was a disaster zone. The President of

the United States declared a state of emergency,

and a FEMA representative then activated and

coordinated the U.S. Urban Search and Rescue

Task Force.

A search and rescue team from Bayamon,

Puerto Rico, arrived at 4:45 p.m. and joined the

rescue operations. FEMA gave interim support

to the local response forces by providing flatbed

trucks for removing the damaged vehicles and

by providing search dogs to help locate missing

people. By 6:00, an advance party of the FEMA

Task Force had arrived, including people from

Florida, New York, and California. At 7:15,

rescue teams reported a strong odor of gas in the

debris of La California store.

At 9, the rescue was suspended again

because of the instability of the building. By

that time, 18 bodies had been found, and more

than 80 people had been transported to area

hospitals. The building was reinforced at

various locations and supported by a crane so

that the rescue could continue. Search and

rescue efforts went on until December 21, when

the bodies of the last four people reported

missing were found, bringing the total of those

who had died in the explosion to 33.

Survival Aspects

According to interviews, because most

stores were not yet open, few shoppers were in

the area at the time of the explosion and many

employees had not yet arrived. The HV building

usually held 50 or more employees, including 37

who worked in the offices, 7 who worked in the

jewelry store, 12 who worked in the shoe store,

and 2 who worked in the record store. Many

other people worked in adjacent buildings, and

hundreds of shoppers and tourists came into or

passed by the building during shopping hours.

Damage

The HV building was destroyed, as was a

major portion of the building that housed La

California. Several other nearby buildings

suffered moderate to severe damage.
12

The first, second, and third floors of the HV

building were shattered, and they dropped into

the basement, as did portions of the fourth floor.

The fifth and sixth floors remained relatively

intact. The building’s structural columns and

beams were severely damaged, and the Puerto

Rico Housing Department declared the building

unsafe and arranged for it to be demolished.

The estimated property damage was

approximately $5 million. Enron Corp. (Enron)10

estimated its property damage as less than

$50,000. Humberto Vidal estimated property

losses to be more than $3.5 million for the

building. The estimates, however, did not

include the following items: Enron’s loss of

sales during the many months that the gas

system was not in service as a result of the

accident, the expenses Enron incurred during

the accident investigation, and Humberto Vidal

merchandise and business interruption loses.

The combined cost of the damage done to

adjacent buildings was estimated to be more

than $1 million, which did not include the

money lost by the businesses that could not

operate for several months after the accident. No

estimates are available about the cost of the

damage done to motor vehicles, the cost of

damage done to windows in buildings on

adjacent blocks, or the costs incurred by the

Civil Defense, FEMA, the Bureau of Alcohol,

Tobacco, and Firearms (ATF), and the Puerto

Rico government agencies that responded to the

emergency.

Personnel Information

Dispatcher.--The dispatcher who received

the leak complaints from the HV building on

November 14 and 20 had been a dispatcher for

26 years and an employee of the SJGC for about

27 years. He stated that his knowledge about his

duties was gained through on-the-job

experience. During 1995 and 1996, he had had

training on how to complete the paperwork

related to his job, and he had been given

pamphlets to read about the SJGC’s procedures.

He stated that the bulletin board at his

 

10Unless otherwise specified, Enron is used to refer to the

Enron Corp. or to any of its predecessor names, such as

InterNorth, Inc.

workstation had all the emergency-response

information he needed.

Technician.--The technician who responded

to the leak complaint on November 14 had

worked for the SJGC for 28 years. In addition to

responding to leak complaints, he installed

stoves and read meters. His on-the-job training

had included his being told how to use

equipment to detect gas and that responding to

leaks is a first priority. His primary trainer had

been the assistant superintendent of operations,

who, in 1996, trained the technician on the use

of a gas detector. The training consisted of inthe-field training in the use of the instrument.

The technician was not tested.

He described his training as consisting of

the assistant superintendent of operations

getting together the four people responsible for

checking gas leaks and installing stoves and

showing them how to use the instrument and

how to check the instrument with gas.

First Brigade Leader.--The brigade leader

on November 15 had worked for the SJGC for

about 40 years. He stated that he did not take the

leak survey training given in January and

December 1996. During 1995 and 1996, he had

been trained in plastic pipe fusion welding,

using a gas detector, and the SJGC’s emergency

procedures. He had not been tested.

Second Brigade Leader.--The brigade

leader on November 20 had been employed by

the SJGC for about 4 years. He had previously

worked for 15 years with a company that

installed fire sprinklers. He stated that at the

SJGC he supervised the work of laborers and

was a pipe fitter. His supervisor, the assistant

operations superintendent, had trained him in

using the CGI. The superintendent taught him

how to test the CGI for accuracy. He was not

tested after his training; based on the assistant

operations superintendent’s observations of his

work, he was allowed to perform field leak

surveys using a CGI.

Third Brigade Leader.--The brigade leader

on November 21 had been employed by the

SJGC for 4 years. He began as a laborer, a

position which he still held at the time of the

explosion, but he was also being trained and

used as a brigade leader. He had functioned as a
13

brigade leader on several occasions before the

explosion. He stated that he had not been trained

in being a brigade leader and had not been tested

to determine whether he understood what the

job entailed. He took field training on the use of

CGIs in January 1996, but did not have to take a

written test. He did not participate in the

December 1996 leak survey training.

MCC.--The MCC had worked for the SJGC

for about 5 years and had held his MCC position

for about a year. Before that, he was a plant

operator. In his present position, he visited

construction sites, estimated what was needed,

assigned a brigade to the work, told the brigade

what equipment it would need, talked to the

supervisor about the work to be performed, and

answered the supervisor’s questions. The

projects he coordinated included repairs and

leak surveys. He also tested the CGIs to ensure

that they were functioning and registering

correctly. He stated that he had attended the

December 1996 leak survey training and was

tested afterwards. He stated that in that training,

he had been taught to make barholes to a depth

of 18 inches and to deepen them if combustible

gas was detected.

Assistant Operations Superintendent.--

The assistant operations superintendent had

been employed by the SJGC since 1975. He had

taken his present position in September 1996

after several months of taking on-the-job

training from the operations superintendent,

who was also being trained for his position. He

had previously been a brigade leader. The

operations superintendent evaluated his work.

He had a copy of the SJGC’s Operations and

Maintenance Manual (O&M Manual) at his

work station, but he had never been tested about

it. He stated that although the SJGC required

supervisors to read the procedures completely,

he had not read either the entire manual or all of

the portions that pertained to his job. He and the

operations superintendent were responsible for

checking supervisors in the field to ensure that

they were performing their work correctly. The

operations superintendent evaluated the

performance of the assistant operations

superintendent, but he did not know whether the

evaluation was written down. He participated in

both the late 1995 and the December 1996 leak

survey training. Written tests were not given for

the 1995 training, but were for the December

1996 training.

Operations Superintendent.--The operations superintendent, who at the time of the accident was being trained for his position, had

been employed by the SJGC since 1968. He began as a draftsman’s helper, and most of his

knowledge had been gained through on-the-job

training. He had been the operations superintendent since the end of April 1996 and had overall

responsibility for operating the gas system. He

stated that he had attended the classroom portion of the 1995 leak survey training, but not the

field portion. He had other assistants, such as

his assistant operations superintendent and the

MCC, there during all of the training. Since the

1995 training, he had taken more leak survey

training in December 1996. During 1995 and

1996, Enron provided him with training on

dealing with reporters, productivity, organizing

his time, delegating authority, and developing

potential in himself and others. For his training

on the SJGC’s practices and procedures, he said,

he had been given a copy of the O&M Manual

and told to study it. He kept a copy of the manual in his office. He was aware that the manual

covered policies and procedures related to work

he supervised, but he had never been tested and

did not discuss with the employees that he supervised their knowledge of the information in

the manual. He had had conversations with the

general manager about what was in the manual,

and he had conversations every morning when

he met with his supervisors to discuss the work

for the day and the relevant SJGC procedures.

Safety Manager.--Before July 1990, the

safety manager had had no experience with

pipeline or propane-gas operations. From July

1990 to August 1992, he had worked for the

Puerto Rico Public Service Commission (PSC).

During his first year with the PSC, he was given

on-the-job training on inspecting companies that

bottled and sold liquid gases. In his second year,

he received on-the-job training from the PSC’s

pipeline inspector on inspecting the SJGC’s

operations. He stated that the training continued

until he learned enough to make the inspections

on his own. In the meantime, he had attended a

1-day session conducted by the Office of

Pipeline Safety (OPS). He stated that while

some of the session involved general

discussions, more of it involved listening to
14

someone from the U.S. Department of

Transportation (DOT) explain the application of

pipeline safety regulations. Participants were not

tested at the end of the session. Of his 2 years

with the PSC, he said, about 60 percent of his

time involved being trained in bottled-gas and

pipeline operations.

In September 1992, he began working for

the SJGC as the safety manager. He worked for

the engineer who operated both the SJGC and

Pro Gas Co. (a bottled gas company affiliated

with Enron). As safety manager, he stated, he

was responsible for personnel safety in both the

field and the office, for gas pipeline safety, and

for public safety as it related to the gas system.

He was responsible for changing the emergency

procedure, updating the contact list,

investigating accidents, familiarizing employees

with the operations manual, working with

supervisors to help reinforce procedures, and

administrating the Federal drug and alcohol

testing. He had read most of the O&M Manual

in detail, but he had never been tested or

otherwise evaluated on his understanding of it.

In both January and December 1996, he

took training in surveying for leaks. In October

1996, about a month before the accident, he

took a course at the Florida Gas Transmission

school on advanced distribution; he was tested

at the end of the course. For 5 to 6 years before

the accident, he had been going to college to

earn a degree in industrial engineering with a

major in quality and safety. He had completed

his course requirements in 1995 and, at the time

of the explosion, was working on his thesis.

General Manager.--Before working for

Enron, the general manager had been an auditor

for two consulting companies: Brown & Root

and Arthur Andersen. He joined Enron in 1987

in an auditing group of an Enron affiliate

company, where he became the director for

commercial development.

In October 1995, he became the general

manager of the SJGC, and he reported to the

president of the SJGC, who also was an

executive of an Enron affiliate company. He

served as a corporate administrator responsible

for operations, safety, human resources, and

finances. He had no pipeline operating

experience, and as the on-site leader of the

SJGC, he viewed his role as one of allocating

resources in a way that would best satisfy

customers’ needs. He stated that he considered

SJGC operations a part of his overall

responsibility, but acknowledged that he had to

rely heavily on the pipeline people that Enron

placed in other leadership and management

positions. He stated that he allocated resources

for functions to be performed but had to rely on

the technical expertise of the operations

superintendent and the safety manager to ensure

that the functions were correctly performed.

The general manager stated that when the

safety director proposed changes in the manual,

he would call someone at Enron headquarters to

review the proposed change and help him assess

whether the change should be made. Similarly,

if the operations superintendent and the safety

manager differed on an issue related to their

responsibilities, he, the general manager, would

contact someone with Enron to assist him in

making a decision. He was not aware that such a

situation had occurred.

Concerning the hiring of consultants for the

SJGC, the general manager stated that he did not

award contracts, that contractors were paid by

Enron, and that after paying them, Enron billed

the SJGC.

Fatigue.--The members of the brigade who

responded on November 21 had had a normal

amount of rest (approximately 8 hours) the night

before. The crew work schedules for the 2

weeks before the explosion showed normal

daytime work hours, a 40-hour work week, and

no changes in work shift.

Training

SJGC Training.--Federal and PSC regulations did not require training for many jobs and

tasks for gas pipeline employees. Employees

were trained at the discretion of the SJGC’s

management. According to the general manager

and the operations superintendent, employees

were selected for training in operations

according to what their regular duties were or

whether they might have to back up operating

personnel. Some supervisors were included in

operations training. The SJGC did not have

general or individual training plans for its

employees.
15

The general manager acknowledged that he

was responsible for employee training, but believed that his role was primarily logistic. That

is, he was responsible for making sure that when

an employee was being trained, the tasks that

the employee normally did were done by someone else. The general manager stated that he

sometimes recommended training for particular

employees, distributed training catalogs, and

discussed with the operations superintendent

who should take what training, but that he relied

on the operations superintendent as having the

primary responsibility for recommending training. He also stated that he relied on consultants,

such as Heath Consultants, Inc., (Heath), for

recommending the type of training a given employee might need. He said that he did some

evaluating of the quality and adequacy of training given to the SJGC employees, but had to

rely on other Enron resources to evaluate the

technical adequacy of the training.

The general manager stated that in his time

with the SJGC, the company had not had a

professional assess the company’s training

needs or decide on the most effective means of

developing training for its employees.

He said that when consultants who did not

speak Spanish trained employees, he made sure

the consultants had adequate translation

resources. During the Heath training, three

bilingual employees helped provide a consensus

translation of the material being taught and

helped convey the information to Spanish

speaking employees. The general manager

acknowledged that the process was far from

perfect.

Enron had a documented skill-based pay

program for its employees, but the program was

not available to the SJGC employees because of

their union contract. Enron also had a computerbased training program, which was not used by

the SJGC employees, and it had access to

classroom training on gas distribution through

the Florida Gas Transmission School, which

some the SJGC employees had attended. (See

also appendix D.)

Leak Survey Training.--At Enron’s request,

on November 28, 1995, Heath proposed that it

provide specialized expertise and function as an

advisor and trainer for SJGC personnel in order

to improve the leakage control program. The

proposal called for a 1⁄2-day classroom session in

gas leak surveying and gas pinpointing and 12

days of hands-on training in leak survey

techniques, including barhole testing, leak

indication, leak classification, and leak

reporting. A January 8, 1996, letter from Heath

to Enron broadened the original proposal so that

specialized training and assistance in various

aspects of the leakage control program would be

provided. The project team would consist of a

technical manager as the on-site supervisor, a

leak pinpointing instructor, and a leak survey

technician, who would be assigned primarily to

leak surveying but would advise SJGC

personnel on other issues concerning leakage

control. Heath would conduct hands-on training

for a minimum of 3 months. Heath’s proposal

was revised later to include 1 day of classroom

training in leak pinpointing and 8 days of handson pinpointing training. All work was proposed

to begin on January 15, 1996.

At Enron’s request, Heath began in

December 1995. Heath’s technical manager met

in San Juan with SJGC management. They

discussed the goals of the proposed project,

reviewed the procedures and guidelines for

surveying leaks, and established the

organization, rotation, and responsibilities for

each of the trainees. The technical manager then

conducted a 1⁄2-day informal classroom review

with the employees who were to be trained. The

instructional material given to the employees

said, “When conducting tests for leakage on

buried petroleum gas systems, it is essential that

samples be taken at or near the pipe, in the

bottom of the ditch lines and at low points of

substructure.”11 The technical manager also gave

hands-on leak survey training. At the end of the

session, he and the SJGC’s general manager

reviewed the field activities conducted between

December 5 and 19.

The technical manager said that the brigade

leaders knew the properties of propane gas,

understood how to lay out barholes, and

understood that barholes had to be drilled to the

depth of the gas lines. He said:

 

11GPTC Guide for Gas Transmission and Distribution

Systems, Appendix G-192-11A, “Gas Leakage Control Guidelines

for Petroleum Gas Systems.”
16

They needed to understand, you know,

the procedures to go through to do the

survey, and what they were trying to

accomplish in doing it [the survey]. It’s

a labor-intensive type of survey, and

you need people who have a keen

interest in wanting to be out there doing

it. They all knew what to do, but not all

of them had the interest. Well, some of

them would rather be digging ditches.

He also said that even though the brigade

leaders knew what to do, only one showed any

interest in leakage surveys. The technical

manager stated that some of the SJGC laborers

did not make the barholes to the depth of the gas

main and had to be re-instructed. Some, he said,

were reluctant to follow instructions and had to

been re-instructed repeatedly about the depth to

which the barholes had to be made.

During January 1996, the technical manager

conducted a 1⁄2-day training session on

pinpointing gas leaks and spent most of the

month with three of the SJGC crews working in

the Old San Juan area. The crews received

hands-on training in pinpointing and surveying

leaks. Heath continued to provide the SJGC

employees with hands-on training during the

surveys they conducted between January and

April.

Gas Company Operations

Gas Distribution and Ownership.--The

first gas pipeline system in Puerto Rico was

installed in 1912. The gas system was initially

owned by the Puerto Rico Gas Company, and it

distributed gas manufactured from coke or coal.

Eventually it converted to a propane/air system.

The system was composed of cast-iron pipe with

steel service lines and was not coated or

otherwise protected against corrosion. Later,

plastic coated steel pipe was installed. The

newer pipes were made of plastic, and the SJGC

has been replacing some of the older mains and

services with plastic.

Enron owns the SJGC, and the SJGC’s

stock is wholly owned by Enron; its

headquarters are in Houston, Texas. Enron was

incorporated as Northern Natural Gas Company

on April 25, 1930, in Delaware. In 1980, the

corporate name was changed to InterNorth, Inc.;

and in 1986, it was changed to Enron Corp. On

or about January 3, 1985, Petrolane

Incorporated sold all outstanding stock of the

SJGC, then a Delaware corporation, to The

Protane Corporation; and it, in turn, on the same

date transferred the assets to InterNorth, Inc.

The SJGC continues to be managed and

operated by its own slate of directors and

officers, and its chairman is the CEO of an

Enron affiliate operation.12

The SJGC distributed a 60-percent

propane/40-percent air mix to customers in the

greater San Juan area through about 220 miles

of gas mains, both low-pressure (1/4 psig) and

high-pressure (20 psig) piping systems. The

low-pressure system that served Rió Piedras

consisted primarily of about 6 miles of 4-inch

diameter cast-iron gas mains and 3.2 miles of

mostly 1 1⁄4 inch diameter galvanized steel

service lines and served approximately 500

customers. The 1 1⁄4 inch inactive bare steel

service lines to the Sbarro on Arzuaga and to the

HV building were connected to 4-inch cast-iron

mains and not protected from corrosion.

Additionally, the steel tee section connecting the

plastic gas main on Camelia Soto to the service

lines for the Chicken Kingdom and for

Comercial Ubiñas was not protected against

corrosion.

Pipes and Ducts Installed on Camelia

Soto.--More than 20 pipes and conduits were

beneath Camelia Soto, some meant for future

use, some being used, and others that had been

abandoned. The conduits meant for future use

included 4-inch and 2-inch polyvinyl chloride

(PVC) plastic pipes of undetermined ownership

and purpose. The pipes and conduits that were

in use included the two water mains, a sewer

main, a plastic gas line, telephone conduits, and

electric conduits. The abandoned pipes and

conduits included a gas main, electric conduits,

sewer laterals, and water service lines. Many of

the abandoned pipes and conduits had not been

plugged or otherwise sealed, which would have

prevented them from being paths for gases that

might have entered the soil. At least five of the

 

12Enron has numerous organizations, many of which use

Enron in their name and which can or do provide various services

to other Enron affiliates. For simplicity, such organizations are

often referred to as Enron affiliate companies.
17

conduits and pipes beneath Camelia Soto

entered the HV building beneath the floor of the

meter room at the southwest corner of the

building. The meter room floor was raised about

2 feet above the first floor of the HV building,

and the space beneath was filled with gravel.

From the gravel-filled space, electrical conduits

entered the HV basement.

According to the SJGC’s records, in

February 1985, the SJGC installed a 1 1⁄4-inch

diameter polyethylene (PE) plastic pipe along

the west side of Camelia Soto. It ran about 2 to

3 feet east of the west curb. Some time later, the

line was extended south by using PE plastic pipe

with PE socket fusion fittings. The extended line

crossed Camelia Soto to provide service to the

business that had occupied the space that the

Chicken Kingdom occupied at the time of the

explosion. To cross Camelia Soto, the line had

to change direction, which was accomplished by

using a 90-degree plastic “ell” socket fusion

fitting.

In 1991, the Puerto Rico Aqueducts and

Sewer Authority (PRASA) installed a 16-inch

diameter water transmission pipeline under

Camelia Soto. The PRASA’s records indicated

that the PRASA had given the SJGC advance

notice that it would be working in the area of

gas pipelines. The SJGC’s maps in the

PRASA’s files for this project showed that a 4-

inch diameter gas main under Camelia Soto was

about 2 feet east of the west curb and ran

parallel to the proposed water line. The

PRASA’s files had no information about the PE

plastic line that the SJGC had installed in 1985.

In 1992, the Puerto Rico Telephone

Company modified its facilities under Camelia

Soto west of the HV building. The company

hired a contractor to install PVC ducts parallel

to the west curb. The contractor’s project

supervisor said that before the work was begun,

the telephone company conducted at least three

pre-construction meetings to inform government

agencies and utilities about the planned work to

ensure that the work was coordinated. He stated

that at one of these meetings, the SJGC

distributed copies of its pipeline maps for the

area and provided telephone numbers to call

should there be any problem. He said the SJGC

said that the maps showed the locations of its

pipes, but, based on his recollections, the maps

did not show all pipe locations accurately. (See

also Tests and Research.) He did not recall the

SJGC representative providing information on

how to work safely around the pipeline, nor did

the gas company mark the locations of its pipes

in advance of the excavation work.

The project supervisor said he first learned

that there were gas pipes in the path of his

project when he found a gas line in an

excavation near the south side of the HV

building. He called the SJGC and was told that

the pipe was an old, unused one. When working

on Camelia Soto, he first learned of the

existence of a small plastic pipe when his

backhoe operator severed it. He stated that he

notified the SJGC and that the gas company

responded very quickly to repair the damaged

pipe. He recalled that the SJGC crew supervisor

stated that the company probably would

abandon that section of gas line in the future.

The project supervisor recalled that due to the

existence of the gas line, he had to alter his

construction procedures by placing some ducts

side by side, rather than on top of one another.

During the project, he said, he called the SJGC

about five times, and the SJGC had to repair

about three leaks. He said that he often had to

use his own excavation equipment to help the

SJGC, as its employees did not bring a backhoe.

Public Education.--The SJGC O&M Manual did not explain how the company would inform its customers and the public about the hazards of propane gas. The manual did not explain

how readers could recognize hazardous conditions or how they could report problems to the

gas company. About 8 months before the accident, in January, the SJGC had started a campaign to educate the public about what to do

when the odor of gas is detected. The SJGC began making announcements in local newspapers,

distributing flyers, including inserts with

customers’ bills, and making presentations to

community groups. The SJGC explained in a

pamphlet that odorants are added to gas to make

its presence detectable. The pamphlet was in

Spanish and was distributed to all customers.

The flyers that the SJGC distributed to the

public before the accident explained that when a

person smelled a strong gas odor, he should:

• Evacuate the area immediately;
18

• Not use any electrical appliance;

• Not smoke or use matches;

• Not connect or disconnect any appliance or

electrical plugs, or any other source of

ignition or flame;

• Not try to repair or stop the gas leak

himself;

• Move to a safe place against the wind and

wait for the arrival of the gas company

personnel; and

• Inform others in the area about the

possibility of a gas leak.

The pipeline safety regulations, 49 Code of

Federal Regulations (CFR) 192.615, require

that operators establish a continuing education

program to enable customers, the public,

appropriate government organizations, and

people engaged in excavation-related activities

to recognize a gas pipeline emergency for the

purpose of reporting it to the operator or

appropriate public officials. The regulations

require that the education program reach all

areas in which the operator transports gas and

that it be conducted in English and in the other

languages commonly understood by the

population in the operator’s area. The operator

must establish and maintain liaison with

appropriate fire, police, and other public

officials for the purposes of (1) learning the

responsibility and resources of each

organization that may respond to a gas pipeline

emergency; (2) acquainting the officials with the

operator’s ability to respond to a gas pipeline

emergency; (3) identifying the types of gas

pipeline emergencies about which the operator

will notify the officials; (4) and planning how

the operator and officials can engage in mutual

assistance to minimize hazards to life or

property.

Emergency Procedures.--Section 7.02 of

the SJGC’s O&M Manual listed the names and

telephone numbers of employees and agencies

to contact in case of an emergency. The list had

not been updated since 1993. In front of the

English version of the manual’s index was a

collection of memos. The memos were not

indexed to sections of the manual, and they

covered such subjects as safety, payroll,

maintenance, emergency procedures, operations,

estimating, suspension of service, and parking.

Some of the memos were not dated; the dates on

the other memos varied from about 1985 to

1993. One of the longer memos was undated and

explained the procedure to be followed in

emergencies. It included a telephone list similar

to the list in Section 7.02.

The O&M Manual told employees to take

immediate and effective action in all

emergencies, such as when gas was detected

inside or near buildings, when there was a fire

or explosion in or near gas lines, or when there

was a natural disaster. It said that in an

emergency, the field supervisor was responsible

for determining which of the following kinds of

action were appropriate: evacuating, eliminating

all sources of ignition, ventilating the area,

locating the gas leak, repairing the gas leak,

coordinating the work with firemen, police, civil

defense, etc., and helping control traffic and

crowds in the area.

According to the manual, “As soon as a

dispatcher or shift guard receives the call or

report he/she should prepare a job order,

indicating the name of the person who called,

his/her address, and the time and date of the

call.” The receiver was to record, in as much

detail as possible, the matter that was reported,

determine the risks that were involved, and

decide whether immediate action was necessary.

If an investigation was necessary, it was to be

done by the shift mechanic. If the shift mechanic

investigated and could not fix the problem, he

was to tell either the dispatcher or the guard,

who was then responsible for telling the shift

supervisor.

According to the dispatcher and the

customer-service representatives, callers were

asked about the location and intensity of the gas

odor. The receivers did not rely on a checklist of

questions to gather the information. The

dispatcher stated that he gave safety tips from

memory and usually gave callers more information than was provided on the safety information

sheets that were given to the dispatchers and

customer-service representatives. The safety tips

provided included:
19

• If you perceive a strong gas odor, evacuate

the area immediately.

• Do not use electrical appliances.

• Do not disconnect any appliance or

electrical plugs.

• Do not use any other source of ignition or

flame.

The dispatcher said that callers were not

told to evacuate a building because the SJGC

did not want to cause unnecessary panic until a

brigade determined whether there was a gas

leak. Also, customers were not informed under

what conditions they should notify local

emergency-response agencies before the

brigades arrived on scene.

Leak Surveys.--The O&M Manual called

for a leak survey each year in high-density or

commercial locations. All other areas of the

distribution system were to be inspected for

leaks at least every 5 years. An annual report of

the survey, indicating the miles of pipe

inspected and the cost, was to be sent to the

SJGC’s general manager.

According to the SJGC management, no

part of Rió Piedras had been surveyed for leaks

between 1994 and 1996. In 1996, the SJGC

surveyed the area with a portable flame

ionization detection unit that sampled the air

from barholes in the pavement. The survey

uncovered 55 leaks, which were then repaired.

Thirteen of the 55 leaks were in the 12-block

area around the HV building. None of the leaks

were adjacent to the HV building.

Previously, in a December 9, 1993, letter,

the OPS encouraged the PSC to use its civil

penalty authority for violations discovered at the

SJGC, an example being the SJGC’s failure to

survey Rió Piedras for leaks. The PSC fined the

SJGC $500.

During the October 1996 inspection of the

SJGC, the PSC noted "unsatisfactory performance about the SJGC’s surveillance and

patrolling of its gas system. The PSC marked

the SJGC’s leak survey program satisfactory;

however, the PSC gave the SJGC unsatisfactory

for its program of surveying business areas, such

as Rió Piedras, each year for leaks.

The pipeline safety regulations, 49 CFR

192.723, require gas operators to survey

business districts each year for leaks and to

survey other areas as often as necessary but at

least every 5 years. In doing the surveys, the

operators must use leak detection equipment.

Odorization.---Section 5 of the O&M

Manual stated that because of the variety of

odorants available, only the engineering

department had authority to buy odorant.

According to the SJGC’s organization chart, the

company did not have an engineering

department. Records show that the propane the

SJGC received from its supplier contained Ethyl

Mercaptan as an odorant, but do not indicate

how much odorant the propane contained. The

SJGC added C.S. Captan odorant; the SJGC’s

procedure did not specify the use of C.S.

Captan, nor was the company able to produce a

document that authorized the use of C.S.

Captan.

The SJGC’s procedures required that

odorant intensity be tested monthly. The SJGC

recorded the amount of odorant and number of

cubic feet of gas/air entering the system daily;

but it did not calculate the injection rate to

determine the amount of odorant added to the

gas. Records indicate that the SJGC began

conducting weekly odor intensity tests in

January 1996.

The O&M Manual did not specify

acceptable minimum and maximum rates of

odorization, establish the acceptable characteristics of the odorant injected, or establish an acceptable range for odor intensity readings obtained during tests. A review of the odorant sniff

test records for the 3 weeks before the explosion

showed four system locations being monitored,

including one for the Rió Piedras area. Records

indicate that the gas odor was detectable when

the propane gas level was at 1/5 the LEL of

propane gas.

The pipeline safety regulations, 49 CFR

192.625, required that gas in distribution lines

be odorized so that the gas could be detected

readily by a person with a normal sense of smell

when the concentration of gas in air was 1/5 of
20

the LEL. The regulations also required operators

to ensure the proper concentration of odorant by

sampling the gas periodically. The PSC

inspected the SJGC’s odorization practices in

1996 and determined that they were consistent

with the requirements.

Excavation-Damage Prevention Program.--In March 1983, the SJGC added Section

8.14, “Program for the Prevention of Damages

to Gas Lines by Contractors,” to its O&M Manual. The program required the SJGC to:

• Maintain an updated list of excavation

companies;

• Communicate with the contractor about the

existence of the SJGC facilities immediately

upon learning of an excavation project;

• Provide, if necessary, at no cost to the

contractor, plans, sketches, and information

to help him locate the buried gas facilities;

as well as mark the location of the buried

facilities;

• Request that companies planning excavations call the SJGC;

• Inspect the project so the integrity of the gas

conduits can be verified;

• Survey for leaks to verify that there are no

gas leaks in the project area.

Copies of this section of the O&M Manual

were to be sent to the PSC; 20 contractors; the

San Juan Regional Office of the Department of

Transportation and Public Works; the

Department of Public Works in San Juan,

Guaynabo, Carolina, and Bayamon; the Electric

Energy Authority; the Aqueducts and Drainage

Systems Authority; the Puerto Rico Telephone

Company; and the Fire Services of Puerto Rico.

On August 8, 1996, a senior safety

representative of an Enron affiliate company

wrote to the SJGC’s general manager that the

O&M Manual should be revised so as to better

protect the SJGC pipelines from being damaged

by contractors and other buried-facility

operators. The letter recommended that the

SJGC:

1. Give the local planning commissions an

O&M Manual and a map of the system, and

have the commissions require companies to

contact the gas company before beginning

work;

2. Try to find out about construction before it

begins;

3. Present procedures and maps to the

Contractors Association membership and

make a presentation, if possible, at a

meeting;

4. Work with upper management at the utility

companies to address the excavation

problem;

5. Buy more pipeline markers;

6. Develop a public education program and

initiate training classes for the public.

The pipeline safety regulations, 49 CFR

192.614, required pipeline operators to have a

written program for preventing damage to

pipelines from excavation activities, including

excavation, blasting, boring, tunneling,

backfilling, removing aboveground structures by

either explosive or mechanical means, and other

earth moving operations. The 1996 PSC

inspection report on the SJGC operations noted

that the SJGC had a satisfactory program.

Gas Maps and Records.--The SJGC

maintained drawings showing the locations of

gas mains, valves, and equipment related to the

gas mains. It kept information related to gas

service lines on cards filed at its San Juan

office. For the most part, the cards had such

information as the gas meter’s size and serial

number, the customer’s name and address, and a

sketch showing the service line size, materials

used, and location. The records of some gas

service lines did not contain sufficient

measurements and references to identify the gas

service lines as they currently existed.

The maps that the SJGC provided after the

explosion showed the gas line on Camelia Soto

being constructed of 4-inch cast-iron pipe. The

map had not been updated to show that the line

had been replaced with plastic pipe. The SJGC

could not locate the service line card for the
21

Chicken Kingdom until several days after the

explosion; the card did have detailed

information about the service line and its

location.

The pipeline safety regulations did not

require operators to have maps or records that

show the locations all major pipeline system

components. Operators were required to have

and maintain maps and records only on some

specific gas system facilities, such as corrosion

control systems.

Corrosion Protection.—Section 4.0,

“Cathodic Protection Policy and Practices,” of

the O&M Manual was dated August 1979. The

section required that the supervisor in charge of

cathodic protection systems supervise the design

and installation of the systems. The SJGC’s

organization chart did not show such a

supervisor, nor did a revised organization chart

that was made available 2 days after the

explosion.

According to the manual, each pipeline was

supposed to be protected by anodes and tested

each calendar year. The manual said that if

annual testing was not practical, protected mains

and services could be tested in sections of not

more than 100 feet. If the section method of

testing was used, at least 10 percent of the total

protected lines had to be tested each year so that

the total protected system would be tested in a

10-year period.

The SJGC had no records of the corrosion

leak history in Rió Piedras or of having done an

electrical survey in the area. According to the

SJGC, it used its leak survey and repair records

in lieu of an electrical survey to identify the

effects of corrosion on its lines. However, the

SJGC did not perform the leak surveys as often

as required by gas pipeline safety regulations,

nor was there any documentation of repair

records being correlated to leak survey findings.

A consultant reported in 1984 to Enron, before Enron acquired the SJGC, that the corrosion control system needed to be upgraded. In

1985, Enron retained another consultant, who

proposed a cathodic protection system. The consultant recommended electrically insulating

portions of the piping system, performing electrical surveys of the system, and setting up a

cathodic protection monitoring procedure and an

employee training program. A cathodic protection survey and master plan were prepared.

The plan included taking such steps as insulating the system, increasing the electrical output

at rectifiers, installing corrosion test stations and

anodes, and training employees in cathodic

protection. The gas company could produce few

records of tests or additional corrective action

taken after 1986 related to achievement of the

consultant’s recommendations.

The pipeline regulations, 49 CFR 192.453,

required that the design, installation, operation,

and maintenance of cathodic protection systems

be carried out by, or under the direction of, a

person qualified by experience and training in

pipeline corrosion control methods. The PSC’s

1996 inspections of the SJGC noted numerous

unsatisfactory conditions relative to corrosion

control procedures, practices, testing, records,

and levels of cathodic protection.

Plastic Pipe.--Section 2 of the O&M

Manual listed the following requirements for the

safe installation of plastic pipe.

• Pipes should be laid on ground free of rocks

that could damage the pipes; the ground

should be firm and provide good continuous

support;

• Pipes should be surrounded by 4 inches of

sand or loose dirt without rocks when laid in

trenches; care should be taken not to

damage the pipe when compacting soil;

• Pipes should be covered by 30 inches of soil

whenever possible and in no case by less

than 24 inches;

• Pipes should have a minimum vertical

distance of 12 inches and a minimum

horizontal distance of 24 inches from any

other buried facility, unless approved by the

inspector; and

• Pipe sections should be cut with proper

tools only and should always be cut straight.

Under the SJGC’s procedures, if steel and

plastic were being connected by a compression

fitting, the steel pipe was to be cleaned and a

special nipple for rigidity (stiffener) was to be
22

inserted into the plastic pipe. The pipes being

joined had to be aligned and inserted at least 1/3

of the way into the fitting. The fitting had to be

tightened, checked for leaks, and wrapped with

special wrapping tape to protect it from

corrosion.

Postaccident inspections revealed that

lengths of plastic pipe in the gas service line to

the Chicken Kingdom were connected by a

compression coupling. After the explosion,

investigators examined the coupling: it was

bare, it was not protected from corrosion, the

ends of the pipe were not evenly cut, stiffeners

were not inserted into the ends of the pipes,

rocks, pavement pieces, and other debris were

near the west side of the pipe, the cover over the

pipe varied in depth between 1 1/2 and 3 feet,

and sand was beneath and adjacent to the part of

the pipe that was in the area that had not been

excavated to install a 16-inch water main under

Camelia Soto.

Abandoned Services.--Section 6.02 of the

O&M Manual was about discontinuing and

abandoning gas lines. It said:

As a general rule, the SJGC procedures

call for service lines that are out of

service for more than 1 year to be

abandoned. They are to be physically

separated from the main and the open

ends of services are to be closed using

plugs.

The SJGC operations superintendent stated

that technicians were told that when they were

investigating leaks, they were to check for

inactive gas services. Any such services were to

be abandoned. Generally, crews closed an

abandoned service by using a mechanical

coupling that had a cap; sometimes they closed

the service with a flexible plastic material that is

used to coat pipe.

The assistant operations superintendent said

that he did not know that the SJGC had a policy

about abandoning inactive service lines.

However, he stated, when a customer said that

gas was no longer to be used at a given location,

the company normally cut the service at the gas

main and plugged the main.

During the investigation, two gas service

lines, one on Camelia Soto and one on Arzuaga,

were found that were inactive and still

connected to the gas mains. A third inactive

service line, on de Diego, had been disconnected

a week before the explosion, but the end of the

service line had not been sealed. The inactive

service on Arzuaga was leaking gas in the area

where it had been damaged by excavation. The

inactive service at Comercial Ubiñas was

connected to the main pipe, which had a

compression fitting that was leaking gas. The

inactive service for the HV building had been

inactive for at least 6 years before it was

disconnected, on November 15, 1996. The

SJGC’s records for 1983 through 1995 showed

that of its 12,000 service lines, 4,000 were

probably inactive but had not been abandoned.

Unaccounted for Gas.--Unaccounted for

gas is the difference between the quantity of gas

that enters the gas system and the quantity that

is delivered to customers or used for other

known purposes. The SJGC reported to the OPS

that it was unable to account for 5.0, 4.7, and

3.5 percent of the gas that had entered its system

in 1993, 1994, and 1995, respectively. The

chairman of the SJGC’s board of directors

testified that in 1995 the SJGC had set a goal of

reducing its unaccounted for gas to 5 percent or

less in 1996. In 1995, the unaccounted for gas

was about 25 percent, and the SJGC chairman

attributed about 7 percent to billing and

metering problems and the remaining 18 percent

to theft.

Meteorological Information

Between November 14 and 21, the

temperature ranged from 72 to 85 degrees F.

Except for November 17 and 18, little rainfall

was recorded during the period. About 0.2 inch

of rain was recorded on November 17, and

about 0.8 inch was recorded on November 18.

Medical and Pathological Information

Injuries consisted of abrasions, contusions,

lacerations, fractures, sprains, dust and gas

inhalation, friction burns, and multiple body

trauma. Survivors were triaged at the scene. Of

the people triaged, 85 were treated at area

hospitals. Sixty-nine people sustained injuries;

25 injuries were classified as serious. An
23

undocumented number of injured people were

treated by private physicians and not seen at

local hospitals.

The 33 fatalities were autopsied at the

Institute of Forensic Sciences in San Juan

between November 21 and December 20.

According to the autopsy reports, the deaths

were caused by traumatic injuries and traumatic

suffocation.

The Caribbean Medical Testing Center

collected urine samples from each of the six

people in the November 21 brigade. Because no

laboratory in Puerto Rico is approved to perform

all required tests, the samples were sent to

Corning Nichols Institute of San Diego,

California, to be tested for drugs. On November

27, all tests were reported negative for drugs.

According to the SJGC, it complied with 49

CFR 199, which requires testing of employees

within 8 hours of an accident or providing a

written explanation of why the employees were

not tested. The SJGC explained that five of the

six employees were injured and seeking medical

treatment. The sixth employee was in the

custody of one of the agencies investigating the

explosion.

Tests and Research

SJGC Pipelines.--After the explosion,

investigators tested the subsurface of the streets

in the area of the HV building in various ways.

They sank barholes as deep as the approximate

depth of the main (2 to 3 feet according to the

SJGC’s records) at intervals of approximately

10 feet along the gas main and positioned them

between the gas main and the nearest street curb

along de Diego, Monseñor Torres, and Arzuaga.

Because the investigating team did not yet know

that Camelia Soto had a gas line that was near

the HV building, barholes were made at 10-foot

intervals along the east curb of Camelia Soto

between de Diego and Arzugua and then along

the west curb from the Comercial Ubiñas

service line northward to de Diego. (See figure

4.)

To determine during the early stages of the

investigation whether propane was present in

the subsurface adjacent to the HV building, the

investigators collected two samples from each

of the three barholes in which the CGI reading

was 100 percent LEL or greater for propane gas.

One set of samples was subjected to

comparative gas chromatography at a local

laboratory, and the results confirmed the

presence of propane in the sample taken from a

barhole at the intersection of Camelia Soto and

de Diego. The second set of samples was

subjected to analytical gas chromatography, and

the results confirmed that propane was present

in all three barholes and was the major

combustible gas constituent in two of the three.

After finishing the CGI tests, under the

direction of Safety Board investigators,

nitrogen13 was introduced into the gas pipes on

de Diego, Camelia Soto, and Arzuaga. (The

nitrogen was under the approximate pressure

that the gas system had been at the time of the

explosion: 7 inches water column.) Those pipe

sections that did not hold pressure underwent

further tests designed to identify possible leak

areas and determine the leak rate. Nitrogen was

generally used to measure the rate of release

from the pipe section, and helium was used to

pinpoint leak locations. Based on the helium test

results, pipe sections were excavated for

examination. If a pipe section was damaged, the

section was removed, the pipe ends were closed,

and the remaining pipe was re-tested until it

held pressure, another release point could be

identified, or sufficient information was

obtained to decide that the remaining leaks

probably had had no effect on the explosion in

the HV building.

When the investigators excavated the

service line to Comercial Ubiñas, they learned

that a steel T-shaped pipe section had been left

in place when the SJGC installed a plastic line.

Compression couplings had been used to

connect the T-shaped section to the plastic line

and the Comercial Ubiñas service line. The

investigators injected nitrogen into the gas main

at the compression coupling south of the

Comercial Ubiñas service line and found that it

took a flow of 1.76 cubic feet per minute (105.6

cubic feet per hour) into the pipe section to

maintain pressure.

 

13Nitrogen flow properties are much closer to those of

propane than to those of helium.

25

When the investigators excavated the pipe

section, they found that the test medium was

escaping from a crack in the plastic pipe in front

of the Chicken Kingdom. The pipe segment with

the crack was removed for later laboratory

testing, and the remaining segments were retested. Nitrogen was then used to determine the

leak rates of various portions of the gas line

between the service to Comercial Ubiñas and

the Chicken Kingdom. (See figure 5.) The

compression fitting at the Comercial Ubiñas

service was determined to leak at 0.04 cubic feet

per minute, and the steel T-section connecting

the plastic leaked 0.02 cubic feet per minute. No

additional leaks were found south of the

Comerical Ubiñas service line to the area of the

crack. Therefore, the undisturbed crack in the

plastic pipe in front of the Chicken Kingdom

was found to have been leaking at a rate 1.70

cubic feet per minute (102 cubic feet per hour).

Further excavation of the Chicken Kingdom

gas service line showed that PVC plastic

telephone conduits had been installed about 15

feet west of the leaking plastic coupling. The

conduits were directly over and in contact with

the gas line, and both the conduits and portions

of the gas line had been buried in concrete. (See

figure 6.) According to SJGC records, the gas

line had originally been installed along the west

side of Camelia Soto to a point where it was

across from the Chicken Kingdom. At that

point, the plastic line was shown to make a 90-

degree turn, crossing under Camelia Soto and

entering the Chicken Kingdom. Excavation

revealed that the service line did not contain a

90-degree tee. Instead of making a 90-degree

turn, the plastic pipe changed direction to enter

the Chicken Kingdom by making a long

sweeping curve, and the two segments were

joined by a compression coupling. The

supervisor for the contractor who had installed

the telephone conduits confirmed during his

interview that he was unaware of any gas line

beneath Camelia Soto because none was shown

on the drawings he had obtained from the SJGC.

He stated that while excavating with a backhoe

to install the telephone conduits, his crew cut

the gas line. He said that he had reported the

incident to the SJGC, which repaired the gas

line. He said that the plastic pipe ran down the

trench in which the telephone conduits were

being installed and that SJGC employees had

told him that the gas line would probably be

abandoned. (See also Pipes and Ducts Installed

on Camelia Soto.)

The 4-inch diameter gas main on Arzuaga,

from a point east of Camelia Soto to a point

about 1 1⁄2 blocks east of Monseñor Torres, and

a short segment of main on Camelia Soto south

of Arzuaga were tested with helium to find out

whether the pipes leaked. The pipes could not

hold pressure with no flow. The pressure was

raised to 7 inches water column, and the flow

rate was measured to be about 4 cubic feet per

hour. Testing the barholes for helium identified

a helium release point in front of the Sbarro

restaurant near the northeast corner of Camelia

Soto and Arzuaga. Excavation in front of Sbarro

revealed a damaged and leaking inactive service

line to the restaurant; the service line leaked at a

rate of 2.06 cubic feet per hour, and the main

east of that point leaked at a rate of 2.83 cubic

feet per hour. (See figure 7.) The main to the

west had a leak rate of less than 0.1 cubic foot

per hour.

Sbarro Restaurant Propane Fuel Lines.--

Sbarro Restaurant used propane gas from

cylinders stored outside the building’s east wall.

The propane flowed into an underground fuel

line and then into the building. While the line

was under test pressure, the outside exposed

portion was checked for leakage using a

soap/water solution. The line leaked at the

above-ground shut-off valve. The valve was

lubricated, and a subsequent test showed no loss

of pressure. Those tests indicated no leaks

underground.

Smoke Migration Tests.--On November 30,

investigators tried to find out whether there

were any direct, underground paths beneath

Camelia Soto from the area of the cracked

plastic pipe into the HV building that might

have survived the explosion. The hole that had

been excavated to remove the cracked plastic

pipe was covered, and a smoke generator and a

blower were used to introduce smoke under

pressure into the adjacent soil. Observers

stationed around the destroyed buildings saw no

smoke exiting buildings or other structures.

On December 1, a second hole, just west of

the southwest corner of the HV building, was

used in smoke migration tests. Similar

procedures as described above were employed,
26

Figure 5. Location of Crack in Plastic Gas Line to Chicken Kingdom.

Figure 6. Plastic Gas Line Entering Telephone Conduit Bundle in Concrete under Camelia

Soto. (Arrows point to the concrete walls on each side of the excavation.)
27

and again no observer saw smoke exiting

buildings or other structures.

Examination of Debris and Retrieved

Damaged Materials.--The day after the

explosion, a team from the ATF examined the

building and its debris for evidence of

explosives. Samples of debris (concrete, plaster,

and a paint can) were sent to the ATF’s Forensic

Science Laboratory, where they were examined

for “any and all explosive residue.” The ATF

also examined the building, using dogs trained

to find explosives. The ATF did not find any

evidence of explosives. Based on those tests, the

use of dogs to detect any explosives in the

debris, and the physical evidence examined in

the HV building, the ATF team determined that

no explosives were used and that damage to the

HV building was the result of a fuel-based

explosion.

Figure 7. Location of Gas Leak from Inactive Gas Service Line under Arzuaga.

In January 1997, Safety Board staff

documented the damage inflicted on the HV

building and recorded the directions of forces,

the damages to structural components, and the

locations where heat had apparently had an

effect. (See figure 8.) There was no evidence of

fire in the building, and the failure direction of

the building’s columns was consistent with that

resulting from overpressure. The building

column and connected beams nearest the east

wall just west of the east stairway, column D-1,

(see appendix E) was the area identified as most

affected by heat. Blackened web-like residue

was on the north and west faces of the basement

column and on some faces of the north and

connected west beams between the basement

and the first floor.

An air conditioner exchange unit that was in

the building when Humberto Vidal bought the

building had been mounted on the west face of

column D-1 before the explosion. The unit had

been mounted 20 inches above the floor, and the

electric fan motor was about 41 inches above

the floor. The thermostat was mounted on a

rectangular piece of plywood on the south face

of this column. The exchange unit was torn from

its mounts by the explosion, and its thermostat

and control wiring showed effects of heat

damage. The plywood surface was
28

Figure 8. Major Crack in West Wall of Basement of HV Building.

scorched, and the thermostat plastic base plate

was deformed.

Also collected were small pieces of

cardboard and insulation material taken from the

southwest juncture of column C-1, north of D-1,

where the first-floor concrete slab once had

joined the connecting beams. Both items

exhibited slight surface scorching. Additionally,

the west half of the surface underneath the

basement beam between columns E-1 and E-2

was noted as having numerous black patterns

typical of shoe soles that were stored in the

basement. (See figure 9.)

In February 1997, while building debris and

damaged merchandise were being removed from

the basement, various synthetic and wood

products items that exhibited heat exposure

damage were removed for further examination.

The items included polyethylene shrink-wrap,

fiberglass, vinyl, nylon stockings, paper,

cardboard, and plywood. The most severe heat

damage to the synthetic materials indicated

exposure to a temperature sufficient to melt

some portions of them. The highest melt

temperature for the synthetics that were

damaged is approximately 220° F. According to

witness observations, the paper, cardboard, and

fiberglass recovered from the debris probably

were damaged in fires accidentally set during

the rescue and demolition operations. Visual

examination of the heat-affected synthetic items

removed from the basement showed that the

heat had been high enough to melt small

portions of the items but not to ignite them.

Laboratory Examination of Failed Pipes.--

The damaged 1 1⁄4 inch diameter plastic pipe

section from Camelia Soto was examined under

Safety Board supervision at the Washington Gas

Materials Testing Laboratory and at the Safety

Board’s laboratory. The exterior surface of the

section had a 1⁄4-inch long circumferential crack

at the interface of a fused socket coupling.

Portions of the socket-to-pipe fusion joint did

not contain the melt roll-out plastic bead that

plastic-pipe manufacturers recommend as a

visual indication of a quality fusion joint. It was

determined that the crack, which went through

the wall of the pipe, had started on the outside

of the pipe and slowly progressed inward. The
29

slow growth of the crack was the result of

excessive bending stress. (See figure 10.)

The wall of the 1 1⁄4 inch diameter steel

service pipe removed from Arzuaga had two

holes; the holes were caused by corrosion. The

pipe had a lateral deflection with an indentation

typical of one caused by excavation activities,

and the part of the pipe that had been damaged

by excavation was corroded.

Oversight and Regulation

Enron.--Several times Enron sent consultants to examine the SJGC and report on its condition. Brief summaries of some of the reports

follow.

Figure 9. Shoe Sole Imprints on Bottom of Beam in Basement of HV Building.

Before deciding to buy the SJGC, Enron

sent a consultant to evaluate the system and the

company’s compliance with the DOT pipeline

safety requirements. The consultant’s report

discussed the PSC’s special concerns about gas

volume accountability and system corrosion

protection and the DOT’s concerns about

corrosion and general system operations. The

report also addressed concerns about the

corrosion protection system, gas volume

accountability, metering accuracy, regulatory

compliance, system safety, and the adequacy of

system pressure control. Among the

improvements the consultant recommended to

Enron were:

1. Eliminate casing and underground electrical

shorts to improve its corrosion protection;

2. Insert plastic pipe into old, leaking, and

corroded pipelines;

3. Abandon all unused service lines that are

still under gas pressure to lessen the chances

of electrical shorts to the corrosion

protection system;

4. Give all employees the training on the basic

fundamentals and corrosion protection that

was earlier given to system management;

5. Develop closer communication with other

buried-facility operators to assist in

protecting buried facilities; and
30

6. In coordination with other buried-facility

operators, establish a one-call excavation

notification system.

During the week of March 11, 1985, the

same consultant and the SJGC representatives

inspected maps, records, and buried piping to

assess the system’s corrosion protection needs,

and the consultant developed a master corrosion

protection plan. In June 1985, he did a corrosion

protection survey, developed a corrosion

protection video training program, developed

recommendations on re-testing protected system

segments, and again recommended using plastic

pipe to replace steel pipe where the steel was

excessively corroded. He also noted that a

corrosion control map should be prepared to

show the locations of corrosion test stations,

insulated fittings, corrosion protected areas,

anodes, and other pertinent information.

Figure 10. Crack in 1 1⁄4 Inch Plastic Gas Service Pipe to Chicken Kingdom.

In 1986, Enron contracted with Interamerican Technical Services to perform a safety audit

of the SJGC system and operations. The

contractor reported that the audit had not

uncovered any major safety problems. The

representative wrote that all of the work then

underway was a step toward complying with

DOT regulations and that the SJGC should have

made real progress by the end of the year. The

contractor concluded the report by pointing out

that the general corporate knowledge of the

experienced workers was being lost by attrition

and that little knowledge was being recorded for

future use. The contractor noted that the lack of

training manuals, emergency procedures, and

drawings might prove to be a problem in the

future. The report included the following

comments and recommendations:

All activities should be documented so

as to support the training of others.

The operations manual is too general to

be effective, as it does not provide the

necessary details, such as who is to take

an action, with what frequency, in what
31

manner, etc. Greater specificity is

needed to guide employees as to when a

safety action should be taken, how to

take the action, and under what

circumstances the action should be

taken. [He summarized his assessment

stating that the existing operation

manual is acceptable, but only in

general terms.] To make the manual

useful, it needs to be complete through

references to other books, industry

manuals, written job descriptions,

company organizational charts, and

other documents.

It is difficult for a supervisor to be

responsible for the safety actions of

others if neither has received complete

training that includes a detailed

description of the job to be done.

The company cannot expect a worker to

do a job safely unless there is a standard

to follow that includes the use of proper

tools and protection equipment. Stepby-step procedures need to be specified

in writing and used as a training tool;

otherwise the trainee cannot be

considered properly trained.

There were no records of accident

investigations for the previous few

years. [He theorized that accidents had

occurred, but no records were being

maintained.]

Protection of anode leads during back

fill operations.

Improved compaction of sand bedding

used to protect plastic pipe installations.

Improved procedures on heat fusing

plastic pipe joints.

Protection of plastic pipe from damage

during insertion.

Job site protection to warn traffic when

work is being performed and to warn

against smoking near job sites.

On-the-job training by supervisors or

fellow workers is not the safest nor most

proper way to train personnel. Such

training methods often will result in

some essential procedures not being

related during training.

There needs to be an emergency plan as

required by DOT.

There needs to be a program for

educating the public on the hazards of

propane gas when released and on what

actions should be taken for safety.

Using a flame ionization leak detector,

survey the business districts, high

pressure pipelines and, by the end of

1986, survey all residential areas.

According to Enron, in September 1995, the

president of Enron Liquid Services began to

evaluate the SJGC and other Latin America

operations. In October 1995, he visited Puerto

Rico, where he reviewed the SJGC’s operations

and met with its general manager (his vice

president of operations). Afterwards, Enron

decided to have a lawyer and an experienced

outside consultant evaluate the SJGC’s

compliance with regulations. Enron also decided

to have an outside consultant assist with a gas

leak survey and leak repairs. Enron selected

Gillispie Ventures, Inc., (Gillispie) as its outside

consultant and Heath as its leak survey

consultant. According to Enron, the construction

engineering manager of the Enron Engineering

& Construction Company was called on to assist

the SJGC with the project.

Around November 1995, in an undated note,

Gillispie told Enron that approximately 40

percent of the service lines were inactive and

that the inactive lines might be the reason for a

significant amount of the unaccounted for gas.

Gillispie suggested that reviewing odorization

records, inspection and maintenance plans, and

incident reports might be useful in “finding” the

unaccounted for gas.

In a November 29, 1995, facsimile, Gillispie

contacted the construction engineering manager

to discuss a proposed unaccounted-for-gas

control program. The proposal described a

three-phase program: (1) a search-and-verify

phase consisting of an above-ground electronic

leak survey to confirm that there were leaks, (2)
32

a leak-pinpointing phase to locate the leaks and

classify them according to severity and repair

priority, and (3) a repair-leaks phase, which

would provide an opportunity to assess the

condition of the pipeline system.

In November 1995, Enron also contracted

with Heath to help with a leak survey, with

determining the location of leaks, and with

repairing the leaks. Heath was also retained to

train the SJGC employees to perform leak

survey work.

Gillispie prepared a report, dated December

27, 1995, on the SJGC’s compliance with

regulations. Enron refused to give a copy to the

Safety Board, claiming that the information was

privileged.

Enron International’s manager of environmental safety, who was responsible for safety

and health matters in six affiliated Enron companies, including the SJGC, audited the safety

of the SJGC’s operations shortly before the

accident. Enron contended that the audit was

done at the request of an Enron attorney, thus

also privileged; Enron refused to provide a

copy. At the June 1997 Safety Board Public Inquiry, an OPS representative was asked whether

the OPS expected pipeline operators to perform

safety audits as a normal operating function. He

replied that operators are expected to conduct

safety audits, and that it is not usual for an operator to claim privilege for such work.

PSC.--The PSC was established to regulate

public service companies, such as the SJGC. Its

procedures were established in the Puerto Rico

Public Service Act of June 28, 1962, as

amended, and in the Commonwealth of Puerto

Rico Uniform Administrative Procedures Act of

August 12, 1988, as amended,. Under those acts,

the PSC can seek administrative remedies in the

enforcement of the pipeline safety requirements.

To enforce compliance with its pipeline safety

regulations, the PSC may chose to:

1. Perform a follow-up inspection;

2. Issue an Order to Show Cause as to why the

company should not be penalized for

violations;

3. File in the Court of First Instance of Puerto

Rico a special procedure seeking professional relief when life, health, safety, or

public welfare needs to be protected.

In 1974, the PSC adopted 49 CFR 192 as the

pipeline safety requirements in Puerto Rico. The

OPS designated the PSC as the agency in Puerto

Rico responsible for the pipeline safety

program. The PSC certified to the OPS that it

would monitor gas company operations through

comprehensive daily on-site examinations or

evaluations.

Comprehensive inspections consisted of onsite examinations of the SJGC’s plans,

procedures, programs, records, physical plant,

and work in progress. Comprehensive

inspections were done throughout the year, and

the results were combined in an annual

inspection report. An SJGC representative

accompanied the PSC inspector during all

inspections and could record the findings for the

SJGC management. The PSC did specialized

inspections as necessary to ensure that identified

problems were corrected; to investigate failures;

and to evaluate the adequacy of designs,

operator training, facility tests, and construction

activity.

The PSC’s certification to the OPS noted

that it would continue revising the gas company’s documents about its inspection and

maintenance, operating and maintenance,

emergency plan, and damage prevention programs. The certification also noted that the PSC

periodically inspected the operator’s maintenance records about leak surveys, leak repairs,

valve maintenance, pressure-limiting and regulating stations, telemetering and recording

gauges, relief device tests, odorization, and corrosion control.

PSC Inspections of SJGC.--The PSC’s records

of its inspections of the SJGC in 1992 through

1996 identified numerous probable violations.

The 1992 inspection uncovered 16 probable

violations; and at least 5 of the 16 were noted in

1993. Probable violation subjects included: (See

appendix B.)

1. Records on telephonic leak notifications;

2. Records on written leak reports;
33

3. Welding procedures and welder qualification tests;

4. Inspection of welds;

5. Qualifying plastic pipe joining procedures

and persons who join plastic pipe;

6. Inspection of gas main construction;

7. Testing of cathodically protected systems;

8. Records on required gas line leak and

strength tests;

9. Performance of leak survey; and

10. Records on leak tests of reactivated gas

service lines.

In early 1992, the PSC inspector who was

the SJGC’s safety manager at the time of the

accident audited the SJGC and noted 16

deficiencies. He told the SJGC general manager

in writing that the SJGC had not scheduled or

executed during the last year the cathodic

protection required by 49 CFR 192.465 and that

the SJGC had not monitored the distribution

system valves as required by 49 CFR 192.747.

He said the SJGC was probably in violation of

the requirement that the adequacy of corrosion

protection be tested. The inspector also told the

general manager that gas system valves had to

be checked and serviced each year and that the

interval between servicing was not to exceed 15

months.

1992 Probable Violations

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On April 16, 1993, the SJGC’s safety

manager reported to the PSC on the progress

made in correcting the probable violations that

he had cited in 1992 while he was a PSC

inspector. After reporting the SJGC’s position

on the noted sections, he said that the SJGC had

repeatedly stated its position of compliance with

the regulations; and he thanked the PSC for

making the SJGC aware of a few

misconceptions.
34

On January 27, 1994, the PSC’s director

wrote to an attorney in the Puerto Rico Office of

Public Interest (the office that initiates legal

action), advising that the September 15, 1993,

inspection of the SJGC had identified three

deficiencies in the area of maintenance:

1. Lack of records of leak survey tests during

the year.

2. Lack of records to show that appropriate

pressure tests had been done on plastic pipe

before the pipe was placed in service.

3. Lack of records about corrosion control.

He wrote that two OPS Southern Region Office

inspectors had been present during the

inspection and that he was submitting the

information so that action could be taken to

cause compliance.

In a February 24, 1994, letter, the SJGC

safety manager responded to the PSC with the

following statements: The CFR did not refer to

the use of any detection equipment. The SJGC

had done leak surveys, and the results would be

available to the PSC. Every plastic pipe that the

SJGC had used complied with requirements.

The physical condition of each pipe was

checked before it was stored and checked again

before it was installed. The SJGC had always

maintained records about its external corrosion

control system, and the records had been

available to the PSC upon request.

The SJGC was fined $500 on August 31,

1994, for its failure to comply with safety

requirements.

The PSC and OPS representatives testified

at the Safety Board’s June 1997 Public Inquiry

that the PSC had inspected the SJGC in 1994,

but that records of the inspection could not be

located. In 1995 and 1996, PSC reports showed,

respectively, more than 80 and more than 50

probable violations. More than 30 of the

probable violations listed on the 1995 report

were listed on the 1996 report, and more than 20

of the probable violations on the 1995 and 1996

reports were on or related to probable violations

that were on the 1992 and 1993 reports. (See

appendix B.) The probable violations listed on

both the 1995 and 1996 reports had to do with

the following subjects: inspection of plastic pipe

installations; protection against corrosion;

monitoring of corrosion control systems;

maintenance of required operating records;

written operations and maintenance procedures;

emergency procedures; investigation of failures;

patrolling of gas system; abandonment of gas

facilities; and protection of cast-iron pipe.

The PSC inspector testified that he could

not understand why he was unable to explain to

the SJGC’s management what the SJGC had to

do in order to comply with the regulations. He

commented that while the SJGC’s employees

needed extensive training in many areas of the

pipeline safety requirements, Enron had

competent personnel who could help the SJGC.

PSC Annual Program Certification.--The PSC

reported the following information about the

SJGC to the OPS in its annual 5(a) Certification.

PSC Annual Program Certification Summary

Certification

Year

No. of Incidents

Reported

No. of Probable

Violations

Found

No. of Probable

Violations

Corrected

No. of

Compliance

Actions Taken

No. of Civil

Penalties or

Assessments

1994 03400

1995 0 2 2 0 2/500

1996 02200

1997 3 69 0 0 0
35

OPS.--In Puerto Rico, the PSC has the

primary jurisdiction over the SJGC pipeline

system, while other pipeline operations, such as

the intrastate liquid lines, are subject to OPS

jurisdiction. The pipeline safety regulations

applicable to systems in Puerto Rico are the

Federal pipeline safety regulations since the

PSC has adopted them.

States participate with the OPS in

administering pipeline safety programs in one of

two ways. A State may certify to the OPS that

its pipeline safety and enforcement provisions

comply with or exceed Federal minimums, that

it inspects specific pipeline operations in the

State, and that it enforces its requirements. The

OPS then views the State as having the primary

responsibility for pipeline safety, and the OPS

monitors the State’s activities annually.

The second manner in which the OPS and a

State can cooperate is for the State to enter into

an agreement with the OPS under which the

State inspects gas operations and the OPS

enforces the correction of the deficiencies the

State identifies. Except for Hawaii, Alaska,

Idaho, and Maine, all States, as well as Puerto

Rico, and Washington, D.C., participate in the

Federal pipeline safety program. About 95

percent of the pipelines in the United States are

under the oversight of State pipeline safety

programs.

The Safety Board gathered from the OPS

and the PSC their records and correspondence

related to the PSC’s compliance monitoring of

the SJGC. The activities were traced back to

1983 and show that an OPS representative

visited Puerto Rico each year. During the OPS

oversight reviews, its representative reviewed

the PSC operations and performed some on-site

reviews of the SJGC’s facilities and operations.

(See appendix C). In the early 1980s, the OPS

told the PSC it was concerned that the SJGC

had a variety of problems: its gas leak repair

activities; the adequacy of its operations,

maintenance, and emergency plans; the lack of

an excavation-damage prevention program; the

adequacy of its pressure regulation and

overpressure protection; its corrosion control;

and its treatment of discontinued service lines.

The OPS also told the PSC that the PSC needed

to do a better job of training its inspector, of

documenting inspection results and keeping

records, and of developing administrative

procedures for processing cases of noncompliance. In correspondence, the OPS

recognized that the PSC had improved its

inspector training, that the SJGC’s compliance

with safety regulations was better, and that the

PSC’s pipeline safety program performance was

significantly improved.

OPS correspondence during the 1990s continued to note deficiencies, both in the SJGC’s

operations and in the PSC’s pipeline safety program. The SJGC activities noted as being deficient from 1990 to 1993 involved corrosion

control, excavation-damage prevention, leakage

surveys, testing of pipe before being placed in

service, installing plastic pipe, replacing castiron pipe, and testing employees for drugs and

alcohol. In 1993, the OPS recommended that the

PSC assess a civil penalty14 against the SJGC for

not surveying leaks in all principal business

districts as required. The OPS told the PSC to

improve its documentation of inspections, promote the development of an excavation-damage

prevention program, and monitor the SJGC to

ensure that it complied with its written procedures on installing plastic pipe.

In 1994, the OPS advised the PSC that it

needed to make major improvements to comply

with pipeline safety requirements. In 1995, after

the PSC documented over 80 probable

violations in the SJGC’s operations, the OPS

advised the PSC that it needed to promote the

development of a damage prevention program

and that the PSC needed a vehicle permanently

assigned to the pipeline staff, but it made no

recommendations for obtaining compliance with

pipeline safety requirements.

In 1996, the OPS arranged for 12 representatives of Puerto Rico government agencies,

including the PSC, to tour two one-call excavation notification systems to learn about implementing excavation-damage prevention programs.

In February 1997, the OPS told the PSC that

in 1996 its program was “generally complying

with the pipeline safety requirements” and that a

 

14The PSC imposed a $500 fine in 1994 on the SJGC for not

surveying leaks.
36

vehicle needed to be assigned to the pipeline

safety program to allow quicker response to

pipeline emergencies and to allow the staff to

work more efficiently.

The OPS began rating State pipeline safety

programs in 1989 to reflect its evaluation of

State pipeline programs. Each program aspect,

such as adequacy of inspections or compliance

enforcement, was assigned a maximum number

of points that the evaluator could award based

on his findings. The State program rating was

determined by dividing the total points awarded

by the total possible points and then expressed

as a percentage. The PSC program ratings from

the OPS regional office were 96 for 1989, 92 for

1990, 91 for 1991, 87 for 1992, 84.2 for 1993,

95 for 1994, 97 for 1995, and 97 for 1996.

Other Information

Humberto Vidal.--Humberto Vidal is a

retail merchandise company that sells shoes,

socks, handbags, and related items. The

company owns more than 30 stores in Puerto

Rico, and its headquarters were on the upper

floors of the HV building.

Emergency-Response Procedures.--The HV

vice president stated that the store manager had

the authority to evacuate the building. He said

that he believed that the manager had been

aware of his authority through verbal

communications, but that the manager had not

received any specific training on the issue.

Humberto Vidal officials stated that they were

not fully aware of the dangers of gas and that

they had not received, either by mail or through

the media, any information from the SJGC or

the local authorities about the dangers of gas.

HV Building.--The HV building had six stories

and a basement. The basement was 12 feet, 11

inches, high, 74 feet long, and 53 feet, 10

inches, wide. It had a plaster drop ceiling that

was 16 inches deep. The south end of the

basement was used to store open boxes of shoes

on shelves for the shoe store above, and the

north end was used to store sealed cardboard

boxes of shoes for other Humberto Vidal shoe

stores. After deducting the space occupied by

beams, columns, and stairs, the basement

contained about 50,000 cubic feet of air space.

HV officials estimated that about 10,800 cubic

feet of space in the basement was used for

storage at the time of the explosion: 7,200 in the

north portion and 3,600 cubic feet in the south

portion.

A 5-ton air conditioner exchange unit was

mounted on the west face of a column just north

of the east stairs, and its thermostat control was

mounted on the south face of the same column.

The unit pulled air from the basement floor,

cooled the air, and sent it through ducts in the

ceiling, to be returned to and re-distributed

throughout the basement. The unit reportedly

was used only 2 to 3 hours a day and when

employees were working in the basement.

The building had a meter room, which was

on the first floor at the southwest corner. The

floor of the meter room was about 2 feet above

the level of the first floor, and the space between

the level of the first floor and the floor of the

meter room was filled with gravel. Many pipes

and other conduits for electric, telephone, water,

and sewer services to the building penetrated the

building’s west wall at the meter room. Some of

the pipes, including one for gas, were for

discontinued utility services. Pipes and conduits

also entered the meter room from the gravelfilled space below the floor, and electric lines

conduits penetrated the basement wall. The wall

separating the space beneath the meter room

floor from the rest of the building was made of

concrete block. Also, there was a joint at each

basement wall and building column juncture.

The basement floor had two small drains into

the soil, one beneath the exchange unit and one

in the southeast corner.

Excavation-Damage Prevention.--During

the investigation, representatives of telephone,

electric, sewer, water, and gas operations

discussed with Safety Board investigators their

methods of notifying other operators of

underground facilities before they started

excavating. They said that the excavation

contractor or utility brigade leader would visit

the gas company and obtain a map showing the

buried facilities in the area of the planned

excavation. The SJGC did not customarily visit

the excavation site, which is necessary if the gas

company intends to mark the locations of buried

gas lines. The SJGC also did not normally

inspect the excavation work as it progressed.
37

During the investigation, there were several

instances in which maps and records of buried

facilities were nonexistent, outdated, incomplete, or not readily available. For instance, the

Puerto Rico Aqueduct and Sewer Authority

map, initially used on scene to locate its

facilities, did not show the 16-inch diameter

high-pressure water main under Camelia Soto.

The investigators found several other 2- and 4-

inch diameter plastic pipes beneath Arzuaga and

Camelia Soto and could not find out who owned

them or what their purposes were.

Puerto Rico does not have a one-call system.

(A one-call system allows an excavator to make

one telephone call and know that all companies

that have underground facilities in the area the

excavator is planning to work on will be

notified. The companies that are notified can

locate and mark the location of their facilities

and take other steps to ensure that the excavator

will not accidentally damage their facilities in

the process of digging.) The OPS had been

supporting underground-damage prevention

legislation in Puerto Rico for many years, at

least since 1983; and the PSC had worked since

1991 to prepare one-call legislation. However,

the proposed legislation had not been enacted by

the government of Puerto Rico.
38

Exclusions

The Safety Board considered two potential

sources for the explosion within the HV

building: an explosive device and combustible

gas. The ATF’s on-site and laboratory

examinations and the Safety Board’s

investigation found no evidence of an explosive

device. The ATF’s examination of the HV

building debris found the explosion to be

consistent with a fuel-based explosion.

The Safety Board identified three possible

sources of combustible gas that could have

fueled the explosion: propane gas from storage

tanks, naturally generated gases from the sewer

system or from deteriorating vegetation, and

propane from the SJGC’s propane/air

distribution pipeline system. The Board

excluded propane from storage tanks because

the only tanks in the area were at the Sbarro

Restaurant and pressure tests confirmed the

integrity of the underground portion of the fuel

line from the tanks. The Safety Board also

excluded naturally occurring gas from the sewer

system or from deteriorating vegetation because

no damage to the sewer system was reported and

because such gases would have had an odor

distinctly different from the odor of the odorant

added to propane that several witnesses reported

smelling in the building before the explosion.

Therefore, the Safety Board concludes that the

explosion was fueled by propane from the

SJGC’s gas distribution pipeline.

The Safety Board also excluded employee

fatigue and employee use of drugs or alcohol as

factors that might have contributed to the

accident. The investigation found no evidence in

support of either issue. The work schedules for

the November 21 brigade for the 2 weeks before

the accident and the interviews with the crew

did not indicate that fatigue was a problem.

Three different crews and one technician

separately made calls at the Río Piedras area.

None of the brigade crew worked extensive

hours, and although temperatures and humidity

in Puerto Rico were comparatively high,

crewmembers were adapted to the environment.

The SJGC did not take urine, blood, or

breath specimens from the incident brigade until

about 8 hours after the explosion. The SJGC

documented two causes of the delay: injured

employees needed time for medical treatment

and uninjured employees needed time to help

with the emergency response. Because of the

delay, the tests for alcohol were not useful. The

body usually eliminates alcohol at a rate of

about 0.015 percent to 0.018 percent per hour.15

Thus, after 8 hours, as much as 0.12 percent to

0.14 percent can be eliminated from the blood

stream. Without a timely alcohol test, neither

the SJGC nor the Safety Board could positively

rule out alcohol as a factor in the accident.

Drugs were not a factor in the accident; the

urine samples tested negative for drugs. Urine

samples for the purposes of drug testing are not

as time sensitive as blood or breath samples for

alcohol testing because the body eliminates

most drugs much more slowly than it does

alcohol. The Safety Board concludes that

neither employee fatigue nor the use of drugs

was a factor in the accident.

In August 1997, the SJGC notified the

Safety Board that “in an effort to expedite the

postaccident drug and alcohol testing procedures of SJGC, a review of current procedures

had been initiated.” The letter said that the

SJGC manager of human resources was responsible for the review and that he would also meet

with representatives of the local hospitals to discuss procedures that would allow postaccident

alcohol and drug testing to be more timely.

According to the letter, the SJGC’s employees

would be trained to understand the importance

of drug and alcohol testing and to know what

was expected of them.

 

15O’Neill, B.A., Williams, A., and Dubowski, K.,

“Variability in Blood Alcohol Concentrations,” Journal of Studies

on Alcohol, vol. 44, no. 2 (1983), pp. 222-230.

ANALYSIS
39

The Accident

This section discusses how propane entered

the HV building and the most likely source of

ignition.

Propane Release Points.--Postaccident

tests identified indications of combustible gas in

the subsurface of both Camelia Soto and de

Diego, and an analysis of gas samples taken

from barholes in those streets showed that

propane was the primary combustible gas.

Postaccident testing also revealed that the gas

system in the area of the HV building leaked,

and subsequent testing revealed piping failures

on Camelia Soto and Arzuaga. On Arzuaga, in

front of the Sbarro Restaurant, an inactive gas

service line that had once serviced the restaurant

leaked through a corrosion hole caused by

excavation damage. According to flow tests, the

line leaked about 2 cubic feet of propane/air an

hour. According to postaccident combustiblegas-indicator and helium tests, the released

propane traveled only a few feet both east and

west of the corrosion hole and along the path of

the 2-inch PVC conduit that had been installed

above and in contact with the inactive service

line.

A compression coupling that connected the

gas main and the inactive service line to Commercial Ubiñas also leaked. The coupling leaked

about 1 cubic foot of propane/air an hour, and

according to postaccident combustible-gas-indicator tests, most of the propane flowed primarily

downhill, along the west side of Camelia Soto,

to de Diego.

The plastic gas line between the Commercial Ubiñas service line and the gas meter for the

Chicken Kingdom was cracked. Postaccident

flow tests using nitrogen established the rate of

release as 1.70 cubic feet a minute (102 cubic

feet an hour). The crack was right above a 16-

inch-diameter water line that had been installed

in 1982 after the plastic service line was. The

crack was at a plastic coupling that had been

used to join two pieces of plastic pipe.

Migration Paths into HV Basement.--

Smoke tests did not reveal a direct path, such as

gas flowing through a conduit, that the propane

could have followed into the HV building.

However, an analysis of the postaccident

combustible-gas-indicator tests shows that

propane escaping from this crack flowed

downhill beyond the HV building. The

migration probably followed pipes under

Camelia Soto and the voids and pipes beneath

the east Camelia Soto sidewalk, at least as far as

the meter room at the southwest corner of the

HV building. The propane probably flowed

along one or more of the active and abandoned

pipes and conduits that entered the HV building

beneath the floor of the meter room. Once under

the meter-room floor, the gas could have flowed

into the basement, following the path of

electrical conduits into the basement. The

propane could have also entered the basement

through joints at columns and wall intersections,

which may not have been effectively sealed.

Although the investigation was unable to

determine the precise path the propane followed

into the HV building basement, the presence of

the odor of propane in the basement is

confirmed by several HV employees.

Fueling the Explosion.--Merchandise and

other combustibles in the vicinity of the

exchange unit were damaged by heat but

showed no signs of having been touched directly

by flame or fire. Consequently, it is likely that

the fuel/air mixture in the basement at the time

of ignition was optimum, about 5 to 6 percent

gas in air, which would have provided a

maximum-force explosion; thus there would

have been little flame or soot. Soot is the result

of incomplete combustion. The volume of the

basement was about 35,000 cubic feet,

excluding space taken up by beams, columns,

storage and shelving, and other solid objects.

Assuming the reported propane/air mix of

the gas transported in the SJGC’s pipeline (60

percent propane gas/40 percent air), the plastic

service line in front of the Chicken Kingdom

was releasing 36.7 cubic feet16 of propane an

hour (0.6 times 61.2 cubic feet per hour).

Assuming that only the propane released from

the crack in the plastic pipe entered the

basement, it would have taken about 57 hours

for enough propane (2,100 cubic feet) to enter to

 

16The test medium (nitrogen) measured flow was not

converted to an equivalent flow rate for propane as there are many

other uncertainties, such as when the leak first occurred and the

rate at which propane entered the building, that would have had

much greater effects on the calculations.
40

raise the gas-in-air level to 6 percent. It is not

likely that all of the propane released from the

crack entered the basement, but there is no

evidence from which the rate of propane

entering the basement can be determined.

Furthermore, there is no evidence about how

long propane was escaping before the odor was

first detected. Nevertheless, the Safety Board

concludes that the 7 days between the time the

SJGC was first informed of the gas odor and the

explosion was more than enough time for that

leak to have produced enough gas to fuel the

explosion. Therefore, the Safety Board

concludes that the propane/air being released

from the cracked plastic pipe under Camelia

Soto entered the HV basement and was the fuel

source for the explosion.

Location of Explosion in HV Building.--

The explosion cracked the columns of the

building and the basement walls about 4 feet

below the top of the basement walls, indicating

that the columns were subjected to severe

bending as the building expanded outward in

response to the expanding internal pressure. The

fracturing of the concrete floor above the

basement, the destruction of the basement stairs

due to an upward force, and the imprints of shoe

soles on the bottom beam face in the basement

indicate that the explosion occurred in the

basement. Heat damage to items in the basement

indicates that the origin of the explosion was at

or near the exchange unit in the basement,

which was near the east wall of the building.

The exchange-unit motor was the only

source of ignition in the area where the

explosion originated. The store manager or the

air conditioner maintenance man had probably

operated the thermostat for the unit about the

time of the explosion. The electric spark

generated when the fan motor was activated

would have been sufficient to have ignited the

propane/air mixture in the basement. Therefore,

the Safety Board concludes that the explosion

was initiated in the basement when the exchange

unit was started in preparation for routine

inspection and maintenance.

Gas Leak Investigation Procedures

The SJGC employees who checked for

combustible gas outside the HV building did not

follow the practices included in the leak-survey

materials provided during their training and in

industry guidance because they did not sink the

barholes to at least the depth of the gas lines.

The November 15 brigade leader did not probe

and test at greater depths, as he should have

when he obtained a combustible gas reading,

and none of the brigade leaders had the barholes

probed to the depth of the gas lines being

surveyed. The failure of the brigade leaders to

follow standard procedures was critical because

the gas system was a low-pressure one; the

pressure in the area of the HV building was

about 7 inches water column. Such pressure is

not enough to drive escaping gas upward from

the point of release. As a heavier-than-air gas,

propane released from the pipe system would

migrate downhill, flowing through voids along

buried pipes and conduits or flowing through

voids in the subsurface. Laboratory tests

confirm that propane was present in the

underground at three subsurface locations in the

vicinity of the HV building. Tests show also that

there were high levels of combustible gas in the

subsurface of the de Diego and Camelia Soto

intersection, both before and after the explosion.

The Safety Board concludes that the SJGC

employees did not detect the underground

migration of propane because they did not

follow the procedures that were included in their

training and in industry guidance on how to

survey for leaks in a low-pressure, heavier-thanair gas system.

Had the SJGC employees who tested the

subsurface on November 15 and 20 tested the

areas adjacent to the HV building at the depth of

the gas lines, as was done in the postaccident

testing, they would have found indications of

combustible gas along the east side of Camelia

Soto, where gas was migrating underground.

Further tests would have identified the crack in

the plastic gas service from which the propane

was escaping, and the service could have been

repaired.

Excavation-Damage Prevention

Postaccident testing showed that excavation

work had damaged the pipeline system in three

areas: under Camelia Soto in front of the

Chicken Kingdom, under the east side of

Camelia Soto at the telephone conduits, and

under Arzuaga in front of the Sbarro Restaurant.
41

The only known event that could account for the

deformation of the plastic service line to the

Chicken Kingdom was the construction of the

16-inch water main in 1992. The main passed

directly beneath the plastic line, and there was

no sand bedding beneath that segment of the

plastic line, as there was beneath other line

segments. The plastic line appeared to have

been deformed by the backfilling or compacting

of soil after it was backfilled over the water

main. Once the plastic line was deformed, its

wall was under stress, initiating a slow-growth

crack in the wall of the pipe. The Safety Board

concludes that the manner in which the water

line was installed imposed excessive stresses on

the plastic gas service pipe, which resulted in

the pipe’s later failure.

The damage to the steel service line on

Arzuaga, which accelerated the on-going

corrosion, was initiated when mechanical

damage, similar to that caused by a backhoe

bucket while excavating, was inflicted on the

pipe. The damage probably occurred when the

2-inch PVC conduit of unknown ownership was

installed.

The plastic pipe near the telephone conduits

had been cut by a contractor in 1992 while he

was excavating in order to install the conduits.

The gas system maps that the SJGC gave the

contractor did not show the plastic pipe, and the

SJGC did not mark the location of the pipe

before the contractor excavated. When notified

of the damage, the SJGC repaired the pipe, but

allowed a major portion of the gas service line

to be intermingled with the telephone conduits

that were being installed and were later encased

in concrete. The SJGC did not disentangle the

gas line from the telephone conduits, ignoring

its own construction practices and gas industry

guidance17 and thus making the gas line

inaccessible for maintenance, leak surveying,

and emergency repair.

Accurate maps are an asset for identifying

the location of buried facilities before

excavation; however, during the investigation,

investigators found several buried facilities for

which the maps and related records were

 

17Gas Piping Technology Committee’s “Guide for Gas

Transmission and Distribution Piping Systems.”

nonexistent, out of date, or incomplete. The

Puerto Rico Aqueduct and Sewer Authority

maps did not show the 16-inch-diameter highpressure water main under Camelia Soto. For 2

days, the SJGC was unable to find its drawings

of the plastic gas line under Camelia Soto, and

some records it produced of gas service lines in

the area were not fully descriptive. Additionally,

no one was able to locate any records that

showed the purpose or ownership of the 2-inchdiameter plastic conduit found in contact with

the gas service line under Arzuaga.

Based on the above observations and

investigators’ discussions with representatives

of the telephone, electric, sewer, water, and gas

operations, the Safety Board determined that

excavators in Puerto Rico do not necessarily

notify operators of underground facilities before

they excavate. Some excavators may give

notice, but if they do, the action is voluntary and

does not follow uniform procedures. For

example, a company or person intending to

excavate near SJGC facilities usually notified

the gas company by informally dropping in to

get a map of the facilities in the area of

excavation. The SJGC did not always respond

by marking the location of its buried facilities in

areas of planned excavation, informing the

excavator about the precautions he should

observe, or periodically inspecting the

excavation site. The responses from the

operators of buried facilities made it clear that

most of them do their own excavating without

notifying the operators of other buried facilities

in the same area. Moreover, the excavationcaused damage to the gas lines under Arzuaga

and Camelia Soto indicate that excavators most

often do not report damage to facility owners;

thus, the owners are not aware of the need to

make repairs.

The Safety Board addressed the need for an

effective excavation-damage prevention program in Puerto Rico in a 1980 Safety Board report.18 In the report, the Safety Board identified

the need for the government of Puerto Rico to

minimize damage to pipelines and other buried

 

18National Transportation Safety Board Pipeline Accident

Report--The Pipelines of Puerto Rico, Inc., Petroleum Products

Rupture and Fire, Bayamon, Puerto Rico, January 30, 1980

(NTSB/PAR-80/06).
42

facilities. The Safety Board recommended on

January 30, 1980, that the Governor of Puerto

Rico:

P-80-87:

Direct the appropriate utilities and

agencies of Puerto Rico to establish an

island-wide one-call excavation notification system.

The Safety Board also made safety

recommendations to The Pipelines of Puerto

Rico, Inc., the PSC, and the Puerto Rico Telephone Company (Safety Recommendations P80-79, -83, and -88, respectively), calling on

them to cooperate with operators of all buried

facilities in establishing an island-wide onecall19 excavation notification system. Although

attempts to initiate the recommended one-call

notification system were made, the attempts

were ultimately unsuccessful, primarily because

of insufficient cooperation among the various

operators of buried facilities and because the

PSC lacked the authority and resources to sponsor such a system. Safety Recommendations P80-79 and -87 were classified “Closed—Unacceptable Action” on April 13, 1988. Safety Recommendations P-80-83 and -88 were classified

“Closed—No Longer Applicable” on July 25,

1988, and May 20, 1984, respectively. The

pipeline company involved in the accident discontinued operations, and the telephone company, although willing to participate in a onecall notification system, stated that it was not

able to undertake the management responsibility

for such an operation.

The Safety Board reviewed the

correspondence between the OPS and the PSC

about the need for an excavation-damage

prevention program. Since at least 1990, the

OPS has been encouraging the PSC to work

with the SJGC and other buried-facility

operators to establish an excavation-damage

prevention program, including a one-call

notification system. The correspondence

 

19In most States, individuals or organizations are required to

notify a one-call notice center before beginning any excavations.

The center disseminates information about the planned

excavations to buried-facility operators, who then have an

opportunity to mark the location of any underground facilities in

the excavation area.

confirmed that the PSC had drafted legislation

requiring excavators to give advance notice of

excavation to operators of buried facilities, but

further action had not been taken. The OPS had

periodically given the PSC information on the

excavation-damage prevention efforts of several

States and had encouraged the PSC to take

similar actions. To encourage Puerto Rico to

implement an excavation-damage prevention

program, the OPS gave the PSC and operators of

buried facilities chances to review State

programs. The OPS also provided grants.

On December 16, 1996, as a result of the

explosion in San Juan, the Safety Board issued

the following safety recommendations to the

Governor of Puerto Rico:

P-96-27

Immediately require that no excavation

(except during emergency conditions)

be made in areas where buried facilities

are likely to exist unless the operators of

those facilities have clearly identified

and marked the facility locations.

P-96-28

Immediately instruct buried-facility

operators to review their maps and

facility records to identify errors and

omissions, to update their system maps,

and to keep their maps up to date.

P-96-29

Immediately require excavators to

promptly notify facility operators of any

damage to a buried facility or its support

caused by excavation operations.

P-96-30

Expedite the implementation of an excavation-damage prevention program

that (1) requires full participation from

all organizations that excavate or that

operate buried facilities, (2) has an island-wide one-call notification center

that accepts emergency notifications 24

hours a day, (3) has effective damageprevention requirements that include
43

government-performed compliance

monitoring and enforcement, (4) incorporates comprehensive education programs for buried-facility operators, excavators, and the public that explain

how to use the damage prevention program, and (5) establishes penalties for

failing to use the program properly.

On January 31, 1997, the Puerto Rico Secretary of State responded for the Governor,

saying that a task force had been established to

develop a plan for implementing the Safety

Board’s recommendations and that the task

force had already made progress. On March 7,

1997, the Safety Board classified the recommendations “Open—Acceptable Response.”

The Secretary of State testified at the Safety

Board’s June 1997 Public Inquiry about the development of a computerized Graphical Information System (GIS) for mapping all buried

utilities in Puerto Rico. The mapping system

includes both government-owned and private

systems, and system operators are required to

keep the GIS current. On October 8, 1997, the

Secretary of State reported that the Governor

had required through Executive Order that all

agencies consult the GIS maps before excavating so as to minimize the opportunity of damaging underground facilities. The Safety Board

acknowledges the mapping improvements made

by Puerto Rico and classifies Safety Recommendation P-96-28 “Closed—Acceptable Action.”

The October 8, 1997, letter from the

Secretary of State said that the Governor’s

Executive Order had also established within the

PSC an Office for the Coordination of

Excavation Works. The office is responsible for

developing procedures on receiving and

disseminating excavation notifications and on

identifying and marking the locations of

government-owned buried facilities in advance

of excavation work. Government agencies must

comply with the procedures the office

establishes. Further, the office is to motivate

private interests to comply with its procedures.

The PSC has established a notification center,

which began receiving excavator notifications

on October 27, 1997. While awaiting the start of

the notification center, the PSC worked with the

government agencies, cable companies, and the

SJGC on coordinating their excavation work so

as to minimize the potential of excavationcaused damage.

The October 1997 letter also said that

legislation has been drafted. If the legislation is

enacted, private interests will be brought under

the same excavation-damage prevention

program as government agencies are under the

Executive Order. The Safety Board expressed its

appreciation of the Governor’s active

participation in resolving the safety issues

identified during the investigation of the Río

Piedras explosion. Safety Recommendations P96-27, -29, and -30 remain classified “Open—

Acceptable Response,” pending implementation

of the anticipated island-wide excavationdamage prevention program.

The Safety Board and the DOT agree that

excavation-caused damage is the major cause of

pipeline accidents. To emphasize the need to

improve State programs, the Safety Board and

the DOT jointly sponsored in 1994 a workshop

to define ways of improving excavation-damage

prevention nationwide and to define the

elements that are essential to an effective

program. The proceedings20 of the workshop,

which were provided to all States and to Puerto

Rico, said that to be effective, an excavationdamage prevention program must:

• Have full participation from all organizations that excavate or that operate buried facilities.

• Have one-call notification centers that

accept emergency notification 24 hours a

day.

• Have effective State damage prevention

requirements that include compliance

monitoring and enforcement.

• Have comprehensive education programs

for buried-facility operators, excavators, and

the public that explain how to use the

damage prevention program and the

penalties for improper use or nonuse.

 

20National Transportation Safety Board, Proceeding of the

September 8-9, 1994, Excavation Damage Prevention Workshop

(NTSB/RP-95/01).
44

The Safety Board encourages the Governor

of Puerto Rico to expedite the activities now in

progress so as to implement an effective, islandwide excavation-damage prevention program as

soon as possible.

Emergency Response

Fire department personnel in Río Piedras

heard the explosion about 8:30 a.m. and

immediately responded. Police officers who

were on scene at the time of the explosion

reacted promptly to help survivors. Additional

police officers, rescue workers, and medical

personnel arrived on scene within minutes of the

explosion, and Puerto Rico’s emergency plan

was quickly and effectively implemented,

including the use of the incident-command

management system.

The government of Puerto Rico quickly

recognized the need for longer-term search and

rescue support. The President of the United

States issued an emergency declaration within

hours of the explosion, which made Federal

disaster support funds and resources available to

aid continuing search and rescue efforts. The

several hours needed to bring search and rescue

personnel and equipment from Florida did not,

in this accident, delay operations, as rescue

workers could not enter the building because it

was not stable. Under other conditions,

however, the time needed to bring search and

rescue support from remote locations could have

interfered substantially with saving lives.

Even though the rescue was hampered by

rain and the instability of the building, workers

diligently searched through rubble and debris

until December 21. They were able to help

survivors and find the bodies of the 33 fatalities.

The Safety Board concludes that the emergency

response was timely and appropriate,

considering the instability of the building.

Survival Aspects

The number of casualties was significantly

influenced by the time of day. When the

explosion occurred, Río Piedras had not become

crowded with shoppers, and employees were

just beginning to arrive for work; most were still

en route or had not yet left their homes.

The location of people influenced the

severity of the injuries they sustained. Of those

within buildings, those on the lower floors of

the HV building were more seriously hurt

because they fell to lower areas when the floors

they were on shattered. Employees on the

fourth, fifth, and sixth floors had a better chance

of surviving than did people on the first, second,

and third floors because the upper floor

structures remained basically intact. People

outside, but in the vicinity of, the HV building

were injured or killed because the force of the

explosion either caused people to strike objects

or to be struck by debris.

The SJGC’s written procedures do not

require dispatchers to gather enough information

from callers to evaluate risks. The dispatcher

who spoke with HV employees about the gas

odor did not obtain information sufficient to

caution them on actions that should be taken

while awaiting the arrival of SJGC response

personnel. He stated that he routinely gave

safety precautions to callers, advising that they

not use electrical appliances, but that had he

been told that the odor was strong, he would

have considered the situation more serious and

would have suggested more precautions. The

Safety Board believes that callers reporting a

gas leak should be instructed, as appropriate, on

immediate response actions to take, regardless

of the perceived strength of the odor, so that

they can evaluate their situation and take

appropriate actions for their safety. Further, the

Safety Board does not believe it reasonable for a

gas system operator to use a caller’s perception

of the strength of the odor as a basis for

determining the urgency of the situation. The

ability of a person to detect an odor varies

according to many variables, including his

perception of “strength,” his innate ability to

detect odors, the effect of being in an

environment that may limit his ability to detect

odors, the quantity of odorant injected into the

gas stream, and the leeching effect of soils on

odorants. Consequently, the dispatcher should

have asked whether people were experiencing

such side effects as nausea and whether the odor

was detected in a confined area. The dispatcher

should have asked for all the information that he

needed to assess whether the building should be

evacuated and whether the help of an

emergency-response agency was necessary.
45

Despite the dispatcher’s claim that he had

given advice, the only surviving HV employee

who had called the SJGC said that the employee

to whom she had spoken gave no advice. The

administrator of the Chicken Kingdom also said

that when he called, the dispatcher gave him no

advice. HV employees who talked with the store

manager after he had complained to the SJGC

said that he had not mentioned receiving any

advice about safety. Instead, the employees said,

the store manager had complained that the SJGC

did not seem to be taking him seriously.

The flyers that the SJGC produced and

distributed did tell readers what to do if they

detected a strong odor of gas. The SJGC

dispatchers and other employees who answered

calls had checklists that listed safety tips and

explained the procedures to follow, including

evacuating buildings. However, the SJGC

employees did not routinely follow the

procedures when they were telling callers the

precautions to take until the site could be

inspected.

The Safety Board concludes that the SJGC

dispatcher did not gather enough information

from the HV employees and consequently could

not assess the severity of the situation or tell the

callers what they should do immediately. An

SJGC employee cannot give reasonable interim

safety advice unless he gathers basic

information from each caller. SJGC employees

must be trained to understand that the caller

usually will not be aware of the seriousness of

the situation or of the precautions that should be

taken. The SJGC employees must form the vital

first line of defense for callers so that the public

will not be harmed by the product the SJGC

supplies.

On February 25, 1997, the Safety Board

recommended that Enron:

P-97-4

Require the SJGC to modify its procedures so that an employee who receives

a call about a gas odor collects enough

information to be able to assess the

danger, advise the caller appropriately,

and determine whether to notify local

emergency-response agencies.

Enron’s May 2, 1997, letter responding to

the recommendation said that all employees

responsible for receiving complaints had

completed a refresher course on responding to

such calls and had completed training on the use

of a revised form. At the June 1997 Safety

Board Public Inquiry, an Enron representative

testified that the checklist had been revised to

encourage dispatchers to take more information

from callers. The Safety Board reviewed the

checklist and noted that it now includes

additional precautionary recommendations, such

as when to call local authorities and the possible

need to evacuate the premises. The Safety Board

classifies Safety Recommendation P-97-4

“Closed—Acceptable Response.”

The store manager demonstrated his concern

about the propane odor by complaining to the

SJGC and to others. However, he apparently did

not fully understand the enormity of the threat

since he took no action to evacuate the store.

His failure to evacuate the store was no doubt

influenced by the SJGC employees who visited

the building during the week before the

explosion and repeatedly told him that there was

no gas in the basement.

The HV employees detected the stronger

gas odors in the basement during the mornings

before the basement air conditioner had been

turned on. Apparently during the first several

days, operating the air conditioner reduced the

odor to the point that it was no longer

detectable. However, according to witness

statements, the odor level and the effects of the

gas concentration on employees increased over

time to the extent that employees who entered

the basement became sick. The store manager

then directed that no employee was to enter the

basement.

No SJGC employees entered the basement

before the air conditioner had been turned on;

but the statement of at least one HV employee

indicates that a brigade leader detected the odor

while he was in the basement. Given that the

SJGC employees knew that people in the shoe

store had complained of gas odors in the

basement, the SJGC employees should have

erred on the side of safety and evacuated the

building until the source of the odor had been

established and the conditions proven safe.
46

According to the SJGC’s emergency plan, if

a gas leak is confirmed, the building should be

evacuated or other actions should be taken. In

the case of the Río Piedras explosion, more than

a week passed before SJGC employees

confirmed the existence of a significant level of

combustible gas in the soil; and at the time of

the explosion, they had not confirmed that the

CGI indication was due to propane gas. HV

employees stated to SJGC employees that the

odor dissipated when the basement air

conditioner was on; yet no SJGC employee

tested the basement atmosphere before the air

conditioner was turned on. The first SJGC

employee to investigate the complaint was the

only one who had an instrument capable of

testing the basement atmosphere. He did not

start and adjust the instrument when he was

outside the building to ensure that it would be

accurate inside the building. Starting and

adjusting the instrument inside the building

meant that it would show only concentrations

greater than those in the shoe store. SJGC

employees who later entered the basement did

not have instruments capable of detecting gas in

such large areas as the basement and thus relied

only on their senses of smell to detect the

presence of gas.

SJGC management, because of the repeated

complaints and because the SJGC employees

failed to identify the cause of the odor, should

have questioned the appropriateness and

thoroughness of the SJGC’s responses and

should have required additional testing of the

basement with appropriate instruments and

before the basement air conditioner was turned

on. SJGC management should also have made

certain that the HV management was aware of

the potential danger and of the symptoms people

may have when they work in environments

containing propane. The gas company’s

management should have told the HV

management about the emergency actions,

including evacuation, that should be taken when

gas odors continue.

The SJGC’s practice of not deciding

whether a building should be evacuated until a

gas leak has been confirmed is not appropriate:

the decision may be made too late, as

demonstrated by the Río Piedras explosion.

SJGC employees need to consider many factors,

with the risk to public safety being paramount,

when evaluating the on-site information to

assess whether an area should be evacuated

before or even during testing. The Safety Board

concludes that Enron needs to require the SJGC

to revise its emergency plan to include

procedures adequate for protecting public safety

any time a gas leak is suspected, including the

need for building evacuations during leak

investigations.

Public Education

Most people interviewed after the accident

who had recognized the odor as being that of

propane indicated that they did not fully

understand that the odor was intended to warn

them of danger and that they did not know what

to do to protect themselves, especially when the

odor was detected inside a building. The SJGC’s

public education program told people what to do

if they smelled gas. A pamphlet explained that

an odorant is used to aid them in detecting gas

leaks and told them how to report problems to

the SJGC. However, the program was not

sufficient because it did not tell people how to

know when emergency responders should be

called.

The HV managers stated that they were not

aware of the substantial threat presented by

propane gas and that the SJGC had not told

them of the danger. The majority of employees

and residents in the area of the explosion

interviewed after the explosion were not fully

aware of the threat posed by a propane gas leak,

and they did not recall receiving information

from any source about what to do if they

smelled gas. The HV managers also stated that

they did not consider evacuating the building

because SJGC employees had not told them of

the danger. The HV managers believed that the

SJGC’s employees would recognize and warn

them of any threats to public or employee

safety, a belief that was reasonable.

Even though the HV building did not have

gas service, the occupants should have known

more about gas emergencies because pipeline

safety regulations required the SJGC to tell the

public, as well as its customers, how to

recognize and respond to the odor of gas. Yet

the SJGC’s customers and non-customers alike

were unaware of the content or existence of the

SJGC’s program. Therefore, the Safety Board
47

concludes that the SJGC’s public education

program did not effectively transmit information

about the dangers of propane gas and about the

steps to take when gas is detected.

As a result of its investigation into this

accident, on December 16, 1996, the Safety

Board recommended that the Governor of

Puerto Rico:

P-96-26

Require information be disseminated to

educate members of the public about the

potential hazards of propane gas and

about actions they should immediately

take to protect themselves and others

when a gas odor is detected.

At the Safety Board’s Public Inquiry, the

Secretary of State for Puerto Rico testified about

the programs that had been initiated in response

to Safety Recommendation P-96-26, and the

PSC also provided information on actions it had

taken. In an October 8, 1997, letter, the

Secretary of State reported on the full array of

actions taken by Puerto Rico. Since the accident,

the Puerto Rico government has taken various

steps to educate the public about recognizing

and coping with a gas leak. The government has

acquired and will distribute hundreds of

thousands of education pamphlets. It has trained

people in government agencies and

municipalities to reach and educate such

emergency first-responders as police, bomb

squads, fire, civil defense, environmental, and

employee-safety personnel. It has given courses

to school children. The local and regional news

media have presented public service messages

and educational articles about detecting and

coping with gas leaks. The Puerto Rico

government has made effective use of the

available media to provide essential safety

information to the public, has conferenced with

all potentially affected government agencies,

and has incorporated on a continuing basis the

teaching of safety information into school

programs. The Safety Board classifies Safety

Recommendation P-96-26 “Closed—Acceptable

Action.”

On February 25, 1997, the Safety Board

recommended that Enron:

P-97-3

Revise the SJGC’s public education

program so that members of the public

understand the danger posed by a

release of propane gas, can tell when

such a release has occurred, and know

when steps, such as evacuating the area

or notifying the local emergencyresponse agencies, are appropriate;

incorporate in the program a means of

measuring its effectiveness.

In a May 2, 1997, letter, Enron stated that it

was employing a public relations firm to

develop a community outreach campaign to

inform the public about the safe use, handling,

and management of propane gas, to establish an

on-going public education program to keep the

community informed about the efforts

undertaken by the SJGC, and to measure the

effectiveness of the program. At the June 1997

Public Inquiry, an Enron official testified that

the SJGC would contribute to an island-wide

public education program if all other petroleum

gas companies also contributed. On July 2,

1997, the Safety Board classified Safety

Recommendation P-97-3 “Open—Acceptable

Response.” On September 30, 1997, Enron

advised the Safety Board that the PSC had

approved its plan to reduce the SJGC’s pipeline

system from a 220-mile one to a 20-mile system

that would serve only commercial customers. In

light of its significantly smaller gas system, it

had modified its public education program. It

now mails customers information twice a year

about the safe use, handling, and management of

propane gas. Once a year, the company sends its

customers a telephone rolodex card that

describes the steps to take should a gas leak be

suspected and a list of emergency telephone

numbers. The company also sends its customers

a “Scratch and Sniff” brochure to remind them

of the smell of the odorant added to the propane

gas. The company sends its customers a flyer

containing safety information in a bullet point

format. Once a year, the company gives the

above-referenced materials to residential and

commercial locations that are near the pipeline

system. Finally, the company contributes to an

island-wide public education program

coordinated by the PSC for educating the public

on the safe use of propane.
48

According to the May 2 letter, Enron has

also distributed more than 25,000 “Scratch and

Sniff” brochures to customers and the general

public. The Safety Board notes the above

improvements in the SJGC’s education

program; however, it is not clear whether Enron

will assess whether the program has reached all

people who may be exposed to the risks posed

by the smaller gas system. The Safety Board

agrees that the island-wide education program

can achieve the results called for by the safety

regulations; however, Enron must monitor the

results of the program to ensure that the

objectives in the regulations are achieved. On

November 4, 1997, the Safety Board advised

Enron that Safety Recommendation P-97-3

would remain classified “Open—Acceptable

Response” and requested Enron to define the

actions it would take to measure the

effectiveness of the island-wide public

education program.

After the Río Piedras accident, Humberto

Vidal put into writing the procedures it had

verbally given its store managers on preventing

injury and illness for employees and the public.

Those procedures provide for:

• Early detection of any hazardous condition

in Humberto Vidal stores.

• Immediate reporting to management of

unsafe conditions.

• Safety and health training to employees,

including drills on what to do in case of an

emergency.

• Specific evacuation procedures to be

developed for each Humberto Vidal

building.

The Humberto Vidal management stated in

a November 7, 1997, letter that it was

formalizing in these procedures the instructions

verbally conveyed to its managers before the

accident on actions they were to take in the

event of an emergency. Tragically, it opined,

even had these written instructions been in place

before the accident, they would have been of

little use in preventing an unexpected explosion

in a building that did not have gas service, did

not store any hazardous materials, and had been

checked several times by the SJGC and found to

be safe.

The Safety Board has addressed in several

reports about accidents the need for better

public education programs, and in a 1990

pipeline accident report21 it recommended that

the Research and Special Programs

Administration (RSPA):

P-90-21

Assess existing gas industry programs

for educating the public on the dangers

of gas leaks and on reporting gas leaks

to determine the appropriateness of

information provided, the effectiveness

of educational techniques used, and

those techniques used in other public

education programs, and based on its

findings, amend the public education

provisions of the Federal regulations.

At a 1992 meeting of Safety Board and

RSPA staffs, the Safety Board noted that gasindustry public education programs appear to

receive less than half the public recognition that

other public safety programs do, such as those

about seat belt restraint and child seat restraints.

Safety Board staff urged RSPA to identify the

techniques that make other public education

programs more effective, determine which of

the techniques would improve gas-industry programs, and then incorporate them into the Federal requirements. On April 5, 1993, RSPA

published Advisory Bulletin ADB-93-02, which

directed “gas pipeline facility owners and operators to review and assess their continuing

education programs as applied to customers and

the public.” The Safety Board did not consider

that action responsive and classified Safety

Recommendation P-90-21 “Open—Unacceptable Action.”

The Safety Board asked RSPA to address

the status of Safety Recommendation P-90-21 at

the June 1997 Public Inquiry. The director of

the Enforcement, Compliance and State

 

21National Transportation Safety Board Pipeline Accident

Report, Kansas Power and Light Company Natural Gas Pipeline

Accidents, September 16, 1988, to March 29, 1989 (NTSB/PAR90/03).
49

Operations Division of RSPA stated that RSPA

had recently received $800,000 in funding to

develop a national public education format to be

used by pipeline operators. RSPA planned to

work closely with industry to determine the

most effective way to educate the public about

handling gas. Although RSPA’s past actions on

this issue have not been timely, the Safety Board

is pleased that the OPS now has on its agenda

the development of a national public education

format and encourages the OPS to expedite

work on this project. Because of the OPS’s

renewed activity, the Safety Board classifies

Safety Recommendation P-90-21 “Open—

Acceptable Response.”

Employee Training

The inadequacy of the training of the

SJGC’s employees contributed substantially to

causing the explosion. Employees cannot do a

proper leak survey or pinpoint a gas leak

without knowing the lateral location of the gas

pipes, the depth of the gas lines, and the depth at

which the barholes should be made. For lowpressure propane/air systems, it is imperative

that a crew first know the depth of the pipeline

and then ensure that the barhole depths reach the

pipe depth. The SJGC employees did not know

the depth of the gas line and did not sink the

barholes deeply enough.

The SJGC’s training was inadequate in

other ways. The company did not assess the

performance of its trainees after they had been

trained or document its training. The personnel

files for the incident crewmembers did include

certificates for various training courses, but the

files did not indicate the content of the courses

or whether the courses were part of a training

plan.

Because the SJGC did not have a written

training plan, the Safety Board could not

determine whether its employees had completed

a prescribed set of courses for their particular

jobs. The certificates in the files did not indicate

whether personnel in certain jobs were all to

receive the same training, as not all individuals

had the same certificates in their files. Test

scores on some training courses for some people

were documented, but not every certificate had

test scores. Interviews with management

indicated that there had been periodic safety

briefings, but the personnel files did not indicate

whether the brigade members had attended the

briefings. The files did not include periodic

reviews of employees’ performance. In all, the

Safety Board found that the employee training

program before the accident was poorly and

inconsistently documented and that no overall

training plan had been established.

The Safety Board assessed the development,

conduct, and evaluation of training for the

SJGC’s employees as inadequate, particularly

for the people who surveyed, located, and

repaired leaks. The major deficiency was the

lack of a front-end analysis of the training

needed. A front-end analysis of a job is

necessary in order to identify the tasks22 that the

holder of the job must be able to do. Once a task

is identified, it can be converted to a learning

objective,23 or a goal that the trainee will

achieve by taking training. Learning objectives

can be used to measure the effectiveness of the

training. If the trainee, after training, can meet

the learning objectives, that is, successfully

perform the tasks that have been identified as

necessary to do the job, the training has been

successful and the trainee is prepared for the

job. Not only does the use of learning objectives

provide a way of assessing the effectiveness of

training, it keeps the training focused on the

tasks that the trainee actually has to be able to

do in order to perform the job. Thus, a good

front-end analysis of a trainee’s job can save

both time and money.

The SJGC had the same problems with the

training for which it had contracted. The

company should have, but did not, require that

Heath assess the performance of the employees

it trained. Heath, having had years of experience

in employee training, should have assessed the

SJGC trainees to determine the knowledge they

already had in the areas being proposed for

training. Had Heath done so, its trainers would

have known whether the SJGC employees

needed advanced training or training on the

 

22A task is an action or function performed as part of a job.

Tasks are usually readily observable and should be measurable for

determining adequacy of performance.

23A statement describes what knowledge the students will

have or what they will be able to do upon completion of training.
50

fundamentals. Doing a job analysis24 would have

identified the individual tasks related to the job,

the number of people needed to perform the job,

the tools and equipment necessary for

performing the work, and any manuals,

references, regulations, or company procedures

the trainees were required to follow.

Heath should have performed a front-end

analysis. The analysis is typically accomplished

using occupational surveys and in-depth

interviews of experienced subject-matter experts

and management personnel. After fully

describing the learning objectives, the course

designer determines the appropriate course

presentation options. Options can include

computer-based training, on-the-job training,

interactive video, slides, and other media, as

well as the standard platform or lecture format.

During this design phase, written testing and/or

ways to assess student performance can be

designed to reflect the agreed upon learning

objectives. In this way, assurance is provided

that all critical job tasks are identified and can

be taught and tested.

Assessing Effectiveness of Training on

Barhole Depth.--When an employee fails to

perform a particular procedure or task correctly,

it is usually an indication the he has not been

trained or that the training was deficient. Poor

performance can also be the result of human

error. In this accident, the crews were not

following the correct leak detection procedure,

which called for making barholes to the depth of

the pipeline.25 The depth of the main line under

de Diego was generally 2 to 3 feet, and some

parts of it were deeper. The depth of the gas line

under Camelia Soto varied from 1 1/2 feet to 3

feet. The brigade leaders indicated that the

barholes they made around the HV building

were about 18 inches deep. The November 15

brigade leader and members stated that the holes

they dug were “18, 20, [and] 19 inches and

sometimes deeper.” Although one brigade leader

 

24Job Analysis: The basic method used to obtain a detailed

listing of duties, tasks, and elements necessary to perform a clearly

defined, specific job, involving observations of workers and

conversations with those who know the job, in order to describe in

detail the work involved, including conditions and standards.

25Appendix G-192-11A “Gas Leakage Control Guidelines for

Petroleum Gas Systems,” GPTC Guide for Gas Transmission and

Distribution Systems.

stated in January 1997 that his crew probed

barholes 2 feet and deeper and that the gas main

was about 2 feet deep, days after the explosion

he told a Safety Board investigator that the

barholes were 18 inches deep. Additionally, the

brigade leader who tested for gas in the barholes

the following day stated that they, like the ones

his crew made, were about 18 inches deep.

The concept that 18 inches is the proper

depth for a barhole appears to be information

that had been internalized by the work crews,

but the Safety Board was unable to determine

the source. A reference (the earliest found) to

barhole depth is included in Heath’s November

1995 work proposal to the SJGC:

Barholes are a minimum of 18 inches

deep, except when the main is less than

18 inches deep, but may need to be to

the depth of the pipe depending on the

soil type and condition as well as the

condition of the pipe, the operating

pressure and the instrument being used.

The brigade workers would not have seen a

copy of this proposal, and Heath’s training

materials26 called for the barholes to be at or

below the depth of the gas main. The materials

do not direct an 18-inch barhole depth. A Heath

consultant maintains that he taught the crews to

penetrate to the depth of the pipe. He also stated

that SJGC employees showed little interest in

performing leak surveys.

After the accident, the SJGC general

manager and Enron’s operations manager asked

Heath to hold training in December 1996 for

designated employees on surveying and

pinpointing gas leaks. Heath trained SJGC

employees in investigating odor complaints,

surveying for gas leaks, pinpointing gas leaks,

and using the SJGC’s newly acquired GMI Gas

Surveyor 434. After each course, Heath gave the

trainees a written examination, which consisted

 

26A copy of Appendix G-192-11A, “Gas Leakage Control

Guidelines for Petroleum Gas Systems,” from the 1990-9 GPTC

Guide for Gas Transmission and Distribution System was

provided as part of the training materials.
51

of multiple-choice and fill-in questions, and

awarded certificates to those who passed.

However, in January 1997, when Safety

Board investigators interviewed SJGC

employees, the brigade leaders still did not

know that barholes should be dug to the depth of

the pipe. On February 25, 1997, the Safety

Board recommended that Enron:

P-97-1

Immediately retrain all SJGC employees

who perform leak detection tasks,

instructing them how to determine

whether propane gas has leaked from

the pipeline system, where and at what

depth to test the subsurface, and how to

define the likely extent of gas migration;

in addition, implement a means of

measuring the effectiveness of the

training provided.

P-97-2

Promptly develop and implement for

SJGC employees who perform operational and safety-sensitive responsibilities a training program that is based on

an evaluation of tasks assigned, so that

it imparts the technical and procedural

information needed to correctly perform

their duties, and that incorporates a

means of measuring the effectiveness of

the training provided.

In its May 2, 1997, response, Enron said that

SJGC employees had had formal classroom and

on-the-job instruction on gas-leak detection and

repair. In its July 2, 1997, letter to Enron, the

Safety Board classified the recommendations

“Open—Acceptable Response.” At the June

1997 Public Inquiry, Enron said that it had

required the SJGC employees to pass tests on

the training they had taken and that employees

who failed were retrained and retested. Therefore, Safety Recommendation P-97-1 is classified “Closed--Acceptable Response.”

At the June 1997 Public Inquiry, an Enron

official testified that the company would soon

complete a comprehensive training and

verification program. Later that month, the

SJGC gave the Safety Board a master training

plan, outlining how the company intended to

develop and conduct training. The program is to

consist of four phases:

Phase One: orientation and mandatory

safety and health training,

Phase Two: fundamentals training,

Phase Three: company overview,

Phase Four: job-specific training.

The plan shows that Enron is systematically

developing a program that includes the use of

front-end analysis and identifies job-specific

tasks, but the plan fails to fully identify job tasks

for some SJGC positions. The plan needs further

clarification and refinement. The plan shows

that the company intends to evaluate employee

performance through written tests, field-skills

verification, and periodic review.

Since the explosion, Enron has demonstrated its understanding of the importance of

developing and documenting training for SJGC

employees, as evidenced by the company’s acceptance of and fast response to the Safety

Board’s emergency recommendations about

training. That Enron offers its own employees

skill-based pay and computer-based training also

shows the company understands the need for

proper training development, as the skill-based

pay and computer-based training were

developed to help improve employee performance. The skill-based pay program was developed using proper front-end analysis and by

involving education specialists, instructional

design specialists, and subject matter experts.

(The program, however, was not available to

SJGC workers.) Having computer-based training

showed that Enron understood the value of

individualized training plans. Further, the

programs demonstrate that Enron had the

knowledge to build effective employee training

programs and, as suggested by its response to

Safety Recommendation P-97-2, could have

earlier extended this philosophy to its affiliate

organization, the SJGC.

The Safety Board recognizes that through

Enron’s extensive work the SJGC program has

progressed rapidly from one having virtually no

documented employee training and qualifica-
52

tions to one that is being systematically planned

and documented. The Safety Board encourages

the developers of the training program to continue refining their identification of employee

tasks, duties, and responsibilities, as such identification is the foundation of the program.

Pending completion and implementation of the

training program, Safety Recommendation P-97-

2 has been classified “Open--Acceptable Response.”

Federal Employee Training Requirements.--In a February 18, 1987, report,27 the

Safety Board recommended that RSPA:

P-87-2

Amend 49 CFR Parts 192 and 195 to

require that operators of pipelines

develop and conduct selection, training,

and testing programs to annually qualify

employees for correctly carrying out

each assigned responsibility which is

necessary for complying with 49 CFR

Parts 192 or 195 as appropriate.

In March 1987, RSPA published an

Advance Notice of Proposed Rule Making,

Pipeline Operator Qualifications (Docket No.

PS-94, Notice 1), which said:

This notice, issued in advance of a

proposed rule, invites public comment

on the need for additional regulations or

a certification program regarding the

qualification of personnel who design,

construct, operate, or maintain gas or

hazardous liquid pipelines.

The Board responded in May, saying that it

had issued 110 recommendations about the

training of pipeline workers. The Board had

issued the recommendations as the result of

various pipeline accidents between 1975 and

1986, and the recommendations covered a wide

variety of training deficiencies that applied to a

broad segment of pipeline activities. The Safety

Board advised that it had found training

 

27National Transportation Safety Board Pipeline Accident

Report, Texas Eastern Gas Pipeline Company Ruptures and Fires

at Beaumont, Kentucky on April 27, 1985, and Lancaster,

Kentucky, on February 21, 1986 (NTSB/PAR-87/01).

deficiencies that were either contributing or

directly causal to pipeline accidents in nearly

every facet of activity investigated, including

operations, construction, and emergency

response. It noted that training and performance

criteria for the pipeline operating community

needed to be developed and implemented so that

the effectiveness of the training and the

performance of the operator could be measured.

The Board said that without such measures it

would be hard to determine objectively whether

training had improved an employee’s

performance and whether the objectives of the

training had been met.

In its comments to the Advance Notice of

Proposed Rule Making and directly bearing on

the SJGC investigation, the Safety Board told

RSPA that it needed to require pipeline

operators to:

• Identify each employee whose successful

accomplishment of assigned responsibilities

or tasks was a necessary part of an

operator’s actions to comply with the

Federal pipeline safety regulations;

• Perform analyses to identify the tasks, jobs,

and responsibilities each employee had that

related to Federal pipeline safety

regulations;

• Identify specific training methods to be

employed to provide each employee with

enough knowledge to effectively carry out

applicable jobs, tasks, and responsibilities

identified in the analyses;

• Identify methods to be used in evaluating

the effectiveness of the training, including

the identification of standards for

acceptance; and

• Document the training provided for each

employee and training evaluations.

On May 11, 1993, the Safety Board

reminded RSPA that it had been more than 5

years since the Board had recommended

establishing employee qualification standards

and that implementing the recommendation

should have been one of RSPA’s top priorities.

The Board affirmed that it remained firmly

convinced that the recommended training,
53

qualification, and testing requirements and

standards were essential. As a result of RSPA’s

inaction, Safety Recommendation P-87-2 was

classified “Open—Unacceptable Response.”

On July 27, 1994, RSPA issued a Notice of

Proposed Rulemaking (NPRM) proposing the

qualification standards for pipeline employees.

On November 9, 1994, the Safety Board

responded to the NPRM, commenting on the

proposal and urging RSPA to expedite

completion of the rulemaking. RSPA received

131 comments on its proposal; and almost 2

years later, on June 25, 1996, it withdrew the

proposal in favor of conducting a procedure

known as “Negotiated Rulemaking.”28 In its

June 26, 1996, Notice of Intent, RSPA stated

that “Commenters to the NPRM stated that the

proposal was too prescriptive and that many

references to training requirements should be

modified to place the focus of the NPRM on

actual qualifications, not the methods of

achieving it.” RSPA selected a committee to

represent the “interests” affected by actions that

it may take on employee qualification

requirements. In April 1997, the committee

began drafting a new rule proposal, but has not

completed its task.

The committee has addressed provisions for

employee performance assessment and

recordkeeping. By requiring the evaluation of

employees’ performance, the committee

addressed the Safety Board’s concern that the

qualifications of employees of pipeline facilities

be judged on the basis of objective,

demonstrable forms of evaluation. The

committee will also recommend that an

evaluation of an employee’s performance be

required if the employee is involved in a

reportable incident to which his actions may

have contributed. In August 1997, the

committee had its fourth meeting. The goal was

 

28 “The negotiated rule process assists in the development of

the NPRM, allowing all affected parties to present their views to

reach a consensus, thus avoiding litigation and disagreement once

the rule is finalized. By using this process the OPS has agreed to

publish the committee’s consensus. Also, the overall contents of

the regulation are the responsibility of the committee. However, by

participating in this process, the OPS does not give up its

responsibility to promulgate the final rule.” Taken from the draft

summary minutes of the April23, 24, 1997, advisory committee

meeting.

to obtain consensus among committee members

on a draft regulation concerning operator

qualifications and to review and revise the

outline for the rulemaking preamble.

If employee qualification requirements are

established, an operator will be able to access

documentation about the training and

qualifications of any employee he is considering

hiring. In an era of downsizing and reductions in

force, the industry should benefit from being

able to know about an employee’s training and

qualifications. The employees will have

credentials that are accessible. In support of the

current employee training and qualification

efforts, a manager of pipeline training29 stated

that having a properly trained workforce adds

tremendous value to a company by reducing the

expense of maintenance, equipment damage,

and personal injuries. Moreover, he added, welltrained employees are usually much more

productive. Needless to say, the public’s safety

would be significantly enhanced if RSPA

ensures that the pipeline workforce is qualified

and trained to carry out its assigned tasks safely.

The Safety Board continues to urge RSPA to

expedite the completion of rulemaking action to

achieve this essential safety objective.

Pipeline Safety Oversight

At the time of the accident, SJGC management did not provide a working environment

that encouraged its employees to adhere to operating policies and practices; management did

not adequately train its employees, and management did not oversee the employees enough

to identify and correct unsafe practices. Of the

three top managers, only the operations superintendent had extensive knowledge of the gas

system, and he had limited management

experience. That environment created by management contributed significantly to the cause of

the accident.

Even though the SJGC management failed

to prepare and motivate its employees, other

entities had chances to correct the deficiencies

before the accident. Enron, the PSC, and the

 

29Gas Industries, U.S. DOT Qualification Ruling, Timothy

Lilly, Manager of Compliance and Technical Training, CNG

Transmission Corporation, January 1997.
54

OPS each had responsibilities for ensuring that

the operations of the SJGC were conducted so

that public safety was not endangered. The

Safety Board concludes that the accident might

have been prevented had Enron, the PSC, or the

OPS been timely in requiring the gas company

to adequately train its employees in leak survey

procedures.

Enron.--Enron, as the owner of the SJGC,

had the corporate and primary responsibility for

ensuring that its affiliate company’s operations

were safe. It had the opportunity and capability

to identify the SJGC’s needs and to make

improvements, either by using SJGC employees

or by calling on specialized or technical

resources, such as legal, regulatory compliance,

and safety, available in corporate groups and

affiliate companies. The SJGC managers did not

know about the older audit findings. They were

heavily dependent on Enron for assistance in

technical and safety matters. However, Enron

affiliate company personnel also did not know

about the previous studies and audits.

Before buying the SJGC in 1985, Enron

management learned of deficiencies in SJGC

operations through a consultant’s audit. After

acquiring the SJGC, Enron used consultants and

Enron affiliate personnel to audit the SJGC’s

operations. Enron affiliate management often

visited the SJGC and met with the SJGC general

manager. Because the Enron affiliate

management reported to Enron management, the

visits allowed Enron to learn about operating

problems, including the results of the PSC’s

inspections. Consequently, it was possible for

Enron management to be aware of the status of

SJGC operations.

The problems that the SJGC had with its

operations before it was acquired by Enron were

not resolved, as they were repeatedly identified

in subsequent audits contracted by Enron

affiliates and in PSC letters to the SJGC.

Corrosion, employee training, construction, and

operation deficiencies continued to be identified

as areas requiring improvement. Even so, Enron

did not act expeditiously to ensure effective

corrections. Toward the end of 1995, Enron

began to improve the SJGC’s compliance with

the safety requirements. Enron management

brought in Enron affiliate and contract resources

to plan and direct the improvement. Enron

wanted to reduce the amount of unaccounted for

gas by improving the accuracy of measurements

and by finding and repairing gas leaks. Enron

also wanted to reduce the amount of damage

that excavation was doing to the pipelines.

While the improvements were needed, they

constituted only a small portion of the

improvements necessary to bring the SJGC’s

operations into compliance with accepted

industry standards and with Puerto Rico’s safety

requirements on employee training, public

education, etc.

Since the explosion, Enron has dedicated

considerable resources to correcting the

deficiencies at the SJGC. Enron, through SJGC

filings to the PSC, requested that it be allowed

to shut down about 200 miles of its 220-mile

distribution system. Enron’s request stated that

the gas system was unable to compete

economically with other energy options

available in Puerto Rico. The PSC has approved

Enron’s plan. The smaller 20-mile gas system

network will provide service only to its

commercial gas customers; however, the

hazards to public safety in the vicinity of the

system will remain. Enron needs to establish a

permanent method of effectively overseeing the

SJGC so as to ensure that its actions are

consistent with public safety requirements and

pipeline safety regulations.

PSC.--Before 1990, the PSC had only one

inspector, and he had many other responsibilities, including overseeing all bottled propane

operations in Puerto Rico. During that time, the

OPS, through its annual audits, appeared to be

doing most of the oversight of the SJGC, and its

representative pointed out several areas that

needed improving. In the early 1990s, the PSC’s

oversight of the SJGC improved: the inspector

had taken extensive training at DOT’s Transportation Safety Institute and a second employee

was being trained as an inspector. The PSC did

not have written procedures to guide its

inspectors on documenting probable violations,

notifying SJGC management of violations, following up violations, and telling the PSC commissioners when formal action was needed to

enforce compliance. Even so, the PSC inspectors did identify, document, and formally notify

the SJGC of probable violations. While the

SJGC did not totally ignore the notices, its responses indicate that it saw little urgency about
55

making corrections. The PSC’s 1992 and 1993

inspections documented 16 and 20 probable

violations, respectively; 5 violations were the

same for both years.

At the OPS’s urging in 1993, the PSC levied

a small monetary penalty against the SJGC in

1994. In 1995, PSC inspectors documented

more than 80 probable violations. A PSC

inspector testified at the June 1997 Public

Inquiry that he had discussed the 1995

inspection results with SJGC management;

however, the PSC could produce no documents

proving that it had either notified the SJGC or

told the PSC commissioners of any need to take

formal action against the SJGC. The PSC did

not take any formal action against the SJGC for

failing to correct the probable violations; and in

1996, PSC inspectors documented almost 60

probable violations. More than 30 were the

same as those documented in 1995. Again, the

PSC was unable to produce written

documentation showing that the SJGC had been

notified; however, a PSC inspector testified that

an SJGC representative accompanied the PSC

inspectors on all inspections and was informed

about all probable violations. Therefore, it

would appear that in both 1995 and 1996, SJGC

management had the opportunity to learn about

the PSC’s findings.

On March 13, 1997, the PSC issued an

administrative order to the SJGC about the 1996

inspection. The order noted that the SJGC had

been told about the areas of non-compliance on

the day of the inspection and that the problems

included corrosion control, operation and

maintenance plans, public education,

investigation of failures, maximum operating

pressure, patrolling, required tests before

restoring gas service, abandoning facilities,

deactivating facilities, protecting metal pipe,

remedial steps, required notifications, and

revision of records. The order stated that the

SJGC was required to eliminate the deficiencies.

The PSC order referred to the Río Piedras

explosion and the Safety Board’s February 25,

1997, recommendation letter to Enron. The PSC

adopted the Safety Board’s recommendations as

part of the administrative order. Using the order

of presentation in the Safety Board’s letter, the

PSC identified the recommendations as items

‘A’ through ‘D.’ Under each item, the PSC

added to, clarified, and emphasized the

individual actions that the SJGC would have to

take to fulfill the intent of the recommendations.

Within 30 days of the order, the SJGC was to

send the PSC a copy of its plans for complying;

thus the PSC could evaluate the SJGC’s

progress.

On April 3, 1997, an attorney for the SJGC

asked the PSC to reconsider its administrative

order on the following grounds: (1) the SJGC

objects to and disputes the contention that it

lacks programs, systems, and appropriate means

to reasonably conduct operations; (2) the SJGC

had informed the PSC that it had fulfilled and

was ready to comply with assignments when and

where required; (3) the SJGC is determined to

certify fulfillment of assignment ‘C’ during or

before April 18, 1997; (4) the SJGC proposes to

coordinate a program comparable to assignment

‘D.’ The SJGC stated that it believed the PSC

should consider these alternatives and meet with

the SJGC to reconsider and revise the order. On

April 30, 1997, after reconsidering, the PSC

ordered the SJGC to comply with the

administrative order.

The PSC’s most recent inspections

demonstrate that it has recognized the need to

inspect SJGC operations more thoroughly;

however, until the explosion, the PSC did not

enforce its safety requirements aggressively.

After the explosion, the PSC ordered the SJGC

to comply with the Safety Board’s

recommendations, but the PSC did nothing to

make the SJGC resolve the probable violations

the PSC had identified in 1995. On May 27,

1996, the SJGC responded to the March 12

administrative order about the 1996 inspection.

The PSC has not yet determined whether the

SJGC has corrected the probable violations or

whether further enforcement action is required.

The Safety Board concludes that the lack of

written guidance for PSC inspectors on

documenting probable violations, on formally

notifying the SJGC, on doing timely followups

to determine whether violations have been

corrected, and on telling the PSC commissioners

when there is a need for formal action to enforce

compliance contributed to poor communications

among PSC staff, its commissioners, and SJGC

management. The lack of effective program

management likely contributed to the ineffective

use of PSC enforcement capabilities and may
56

have contributed to the failure of Enron and the

SJGC to correct deficiencies. The Safety Board

believes that the PSC must develop written

procedures to guide its staff’s actions if it is to

ensure that monitoring will be effective, that the

SJGC will be notified of its probable violations,

and that the commissioners will take prompt,

aggressive enforcement steps if the SJGC fails

to make timely corrections in its operations.

OPS Oversight of State Pipeline Safety

Program.--The OPS is responsible for

evaluating the PSC’s pipeline safety program.

At the June 1997 Public Inquiry, the OPS

southern region director, whose responsibilities

include overseeing Puerto Rico, advised that it

is essential to the success of a program, as well

as a requirement of the certification, that the

agency be able to enforce the regulations by

levying civil penalties as appropriate. He also

said that if a State finds violations but does not

notify the operator and follow up to make sure

the violations are corrected, the OPS will call

the deficiency to the attention of the PSC.

The region director said that the PSC’s

program has improved steadily since 1992.

“Today, there is more support from the PSC

commissioners for the pipeline safety program,

and this is especially true for the past couple of

years since one commissioner pledged his

cooperation to the OPS and his support for the

pipeline safety staff.” Based on his review of the

correspondence between the PSC and the SJGC

about the probable violations, the region

director said, the SJGC needs to improve its

technical knowledge significantly in order to

understand the pipeline safety regulations.

The director of OPS’s Safety Enforcement

Compliance and State Operations Office stated

at the Public Inquiry that the OPS has less than

40 inspectors with which to cover the entire

country. If a State does not certify to perform

intrastate inspections of gas pipeline operators

and enforce pipeline safety requirements, the

OPS is required to do it. Consequently, the OPS

will work with a State program until the State

almost turns it back to the OPS. He added that

that does not mean the OPS will let things go on

that should not. Rather, the OPS works with the

State to improve the program to get its support.

The OPS does everything it can to keep from

decertifying a program. He stated that one

reason the OPS works hard to keep the program

with the States is that the OPS believes that

operator response is better and that a State

usually has much greater resources than the OPS

does.

Each year, the OPS evaluates the PSC’s

performance during the previous year. During

the 1970s and 1980s, the OPS sent letters to the

PSC specifying the deficiencies in SJGC

operations and followed up with the PSC to

ensure that corrective action had been taken.

Based on the OPS’s letters to the PSC in the

1990s, the OPS concentrated, almost to the

exclusion of all other needs, on obtaining

equipment to enable PSC staff to better perform

its inspections and on establishing an

excavation-damage prevention program for

Puerto Rico.

Although the OPS has been trying to

improve the PSC’s pipeline safety program,

since 1993, the OPS has given the PSC’s

pipeline safety program high scores despite

significant deficiencies. The problem was

compounded by the OPS’s letters to the PSC’s

president; the letters gave no indication the

program needed significant improvements, such

as the development of a written procedures to

guide its staff on documenting and notifying an

operator of probable violations or the

development of an effective enforcement

program.

The OPS did notify the PSC in 1993 of its

concern about the PSC’s 1992 inspection

findings of 16 probable violations, and it

advised the PSC that it should seriously

consider using civil penalties to force the SJGC

to make corrections. As a result, the PSC did

levy a monetary penalty. Since then however,

the OPS has not recommended that the PSC take

any enforcement actions, even after the Río

Piedras explosion. Based on its latest evaluation,

the 1996 evaluation, the OPS awarded the PSC a

rating of 97 for its pipeline safety program,

including giving it the highest possible rating for

its compliance program. The OPS awarded these

ratings even though the PCS in 1996 had told

the SJGC that it had more than 50 probable

violations, of which more than 30 had been

identified in 1995, and the PSC had not taken

any formal action to force the SJGC to make

corrections.
57

The Safety Board agrees with the OPS that

the States do provide more resources than the

OPS does for monitoring pipeline operations

and that when possible, the responsibility for

monitoring should remain with the State.

However, the OPS retains overall responsibility;

and through its monitoring of State programs, it

must ensure that pipelines are operated in a

manner that provides adequate public safety.

The Safety Board also agrees that the OPS

should work with the States to help them

maintain and improve their programs. However

at no time should the OPS’s objective of

keeping States in the pipeline safety program

take precedence over its responsibility for

ensuring that pipeline systems are safely

operated and maintained to preserve public

safety.

Each year, after the OPS had evaluated the

PSC’s pipeline safety program, it scored the

program’s effectiveness and gave the PSC

president a numerical grade. The PSC’s

enforcement program received the maximum

allowable points in each of the 3 years. For the

past 3 years, the PSC’s pipeline safety program

received overall scores of 95, 97, and 97,

respectively. The scores would indicate little, if

any, need for improvement. The Safety Board

concludes that the OPS’s evaluation scores for

the PSC before the Río Piedras explosion misled

the PSC commissioners about the need to bring

enforcement action against the SJGC.

The OPS may have given the PSC program

high ratings because the questions on the OPS’s

evaluation form were poorly designed and

because the OPS’s evaluators lacked written

guidance on how to rate various aspects of a

State program. The evaluation questions that the

Safety Board reviewed were loosely framed, and

the evaluators’ assessments of the answers

seemed to be subjective rather than based on

specific, uniform criteria.

When a State program is not functioning,

the OPS must fill the gaps; any time public

safety is being compromised, the OPS must act.

The Safety Board believes that in view of the

events preceding the Río Piedras explosion, the

OPS must improve its State pipeline safety

certification program. The OPS must develop

written guidance and criteria that its personnel

can use to evaluate State programs objectively,

and the OPS must require States to be prompt in

correcting identified program deficiencies.

The Safety Board concludes that the OPS

failed to effectively monitor Puerto Rico’s

pipeline safety program. The Safety Board is

concerned that the deficiencies in the PSC’s

pipeline safety program were allowed to exist

for so long without the OPS recognizing them

and notifying the PSC commissioners about the

need for corrective actions. The Safety Board

concludes that the Río Piedras accident might

have been prevented had the OPS been timely in

notifying the PSC commissioners that the

ineffectiveness of the PSC’s enforcement was

endangering public safety and had it insisted

that the PSC require the SJGC to promptly

correct all deficiencies. Had the PSC’s oversight

been effective, the SJGC brigade leaders might

have been properly trained in detecting

subsurface gas leaks, and thus able to locate and

repair the gas leaks on Camelia Soto before the

explosion. Therefore, the Safety Board believes

that the OPS needs to reassess the effectiveness

of its State monitoring program.
58

Findings

1. Neither employee fatigue nor the use of

drugs was a factor in this accident.

2. The explosion was fuel based; it originated

in the basement of the Humberto Vidal

building and was probably initiated when

the basement air conditioner unit was

operated.

3. The source of fuel for the explosion was the

mixture of propane and air that leaked from

the failed plastic gas service pipe to the

Chicken Kingdom Restaurant and probably

migrated underground into the meter room

of the Humberto Vidal building and then

into the basement.

4. The 1992 backfilling and compacting of soil

over the 16-inch water line imposed

excessive stresses on the plastic gas service

pipe to the Chicken Kingdom Restaurant,

stresses that later caused the service pipe to

fail.

5. The gas company’s employees were not

properly trained in testing for leaks; they did

not test correctly, and they did not find and

repair the leak.

6. The gas company employee who received

telephoned reports of gas odors failed to

provide effective instruction to callers on

the dangers of propane and the steps to take

to protect themselves because neither

employee training nor supervision was

adequate.

7. The gas company dispatcher who talked to

callers reporting gas odors did not give

adequate advice to callers partly because he

did not gather enough information from the

callers to evaluate the seriousness of the

situation.

8. The gas company’s public education

program was not effective in warning

people who had reported a gas odor about

the dangers of propane gas and about the

steps to take when gas is detected.

9. The response from local, Puerto Rico, and

Federal emergency responders was timely

and appropriate, given the building’s

instability and the weather. The time

required for Federal emergency responders

to arrive on scene did not hamper the search

and rescue efforts in this instance.

10. The gas company’s employees were not

adequately trained in surveying and

pinpointing leaks.

11. The leak detection training given to the gas

company’s employees was inadequate partly

because neither the company nor Heath

Consultants, Inc., identified the tasks for

which the employees needed to be trained or

tested the employees to make sure the

training had been effective.

12. Enron Corp. did not provide a working

environment that encouraged the employees

of the gas company to follow its operating

policies and practices strictly, and it did not

oversee employees’ actions enough to

identify and correct unsafe practices.

13. Although Enron Corp. had known since

1985 that the gas company’s operations did

not comply with pipeline safety

requirements and recommended industry

practices, it failed to require the gas

company to comply.

14. Enron Corp. had begun before the explosion

to correct some deficiencies in the gas

company’s operations, but its attempt was

neither timely nor sufficient.

15. In 1995 and 1996, the Puerto Rico Public

Service Commission found numerous

probable violations in the gas company’s

compliance with pipeline safety

requirements, but the Commission did not

require timely, effective corrections.

16. The Puerto Rico Public Service

Commission’s inspectors did not have

written guidance on documenting probable

violations, on formally notifying the gas

company of violations, on doing timely

followups to determine whether violations

CONCLUSIONS
59

had been corrected, and on telling the

commissioners when formal action was

needed to enforce compliance; the lack of

written guidance contributed to poor

communications among the staff and

commissioners of the Puerto Rico Public

Service Commission and the management of

the gas company.

17. The Research and Special Programs Administration/Office of Pipeline Safety failed

to effectively monitor Puerto Rico’s pipeline safety program.

18. The evaluation scores that the Research and

Special Programs Administration/Office of

Pipeline Safety gave the Puerto Rico Public

Service Commission mislead the

commissioners about the adequacy of its

pipeline safety program and about the need

to take enforcement action against the gas

company.

19. The accident might have been prevented had

the Research and Special Programs

Administration/Office of Pipeline Safety

been timely in notifying the Puerto Rico

Public Service Commission that the

ineffectiveness of its enforcement was

endangering public safety and had the

Research and Special Programs

Administration/Office of Pipeline Safety

insisted that the Puerto Rico Public Service

Commission require the gas company to

promptly correct all deficiencies.

20. The accident might have been prevented had

Enron Corp., the Puerto Rico Public Service

Commission, or the Research and Special

Programs Administration/Office of Pipeline

Safety been timely in requiring the gas

company to adequately train its employees

in leak survey procedures.

Probable Cause

The National Transportation Safety Board

determines that the probable cause of the

propane gas explosion, fueled by an excavationcaused gas leak, in the basement of the

Humberto Vidal, Inc., office building was the

failure of San Juan Gas Company, Inc., (1) to

oversee its employees’ actions to ensure timely

identification and correction of unsafe

conditions and strict adherence to operating

practices and (2) to provide adequate training to

employees. Also contributing to the explosion

was (1) the failure of the Research and Special

Programs Administration/Office of Pipeline

Safety to oversee effectively the pipeline safety

program in Puerto Rico, (2) the failure of the

Puerto Rico Public Service Commission to

require San Juan Gas Company, Inc., to correct

identified safety deficiencies, and (3) the failure

of Enron Corp. to oversee adequately the

operation of San Juan Gas Company, Inc.

Contributing to the loss of life was the

failure of San Juan Gas Company, Inc., to

inform adequately citizens and businesses of the

dangers of propane gas and the safety steps to

take when a gas leak is suspected or detected.
60

As a result of this investigation, the

National Transportation Safety Board makes the

following recommendations:

--to the U.S. Secretary of Transportation:

Improve the Department of Transportation’s State pipeline safety evaluation

program by developing written guidance

and evaluation criteria to assist the

Research and Special Programs Administration/Office of Pipeline Safety

personnel in objectively evaluating

State programs and in requiring States

to promptly correct identified program

deficiencies. (P-97-5)

--to the Research and Special Programs

Administration:

Modify your monitoring of State

pipeline safety programs to ensure that

the States are timely in monitoring the

correction of identified safety

deficiencies and to ensure that they

implement enforcement action as

necessary. (P-97-6)

Complete a final rule on employee

qualification, training, and testing

standards within one year. Require

operators to test employees on the safety

procedures they are expected to follow

and to demonstrate that they can

correctly perform the work. (P-97-7)

Require that San Juan Gas Company,

Inc., take action necessary to ensure that

abandoned pipelines are properly

disconnected, purged of propane, and

adequately secured to prevent the

transmission of flammable vapors and

gases, and to ensure that abandoned

pipelines are properly identified on

maps. (P-97-8)

--to the Puerto Rico Public Service Commission:

Develop written procedures to guide

pipeline inspectors in assessing the

compliance of gas pipeline operators

with pipeline safety requirements, in

documenting probable violations, in

notifying gas pipeline operators of

probable violations, and in

recommending to the commissioners

any formal action that may be required

to obtain prompt compliance. (P-97-9).

Require that San Juan Gas Company,

Inc., take action necessary to ensure that

abandoned pipelines are properly

disconnected, purged of propane, and

adequately secured to prevent the

transmission of flammable vapors and

gases, and to ensure that abandoned

pipelines are properly identified on

maps. (P-97-10)

--to Enron Corp.:

Require San Juan Gas Company, Inc., to

include procedures in its emergency

plan that its employees can use in

determining whether a building or area

should be evacuated when a gas leak is

suspected. (P-97-11).

Require San Juan Gas Company, Inc.,

when soliciting a training proposal, to

require that the proposal include plans

for identifying the tasks for which the

trainees must be trained and for

assessing the job performance of the

trainees and the effectiveness of the

training. (P-97-12).

--to Heath Consultants, Inc.:

Identify, when developing contracted

training, the tasks for which the trainees

must be trained and develop measures

for assessing the job performance of the

trainees and the effectiveness of the

training. (P-97-13)

RECOMMENDATIONS
61

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

JAMES E. HALL

Chairman

ROBERT T. FRANCIS II

Vice Chairman

JOHN A. HAMMERSCHMIDT

Member

JOHN J. GOGLIA

Member

GEORGE W. BLACK, JR.

Member

December 23, 1997

For additional information regarding this accident, see NTSB special investigation report Brittle-Like Cracking in Plastic Pipe 

for Gas Service, NTSB/SIR-98/01.

63

APPENDIX A

Investigation and Hearing

Investigation

The National Transportation Safety

Board was notified on November 21, 1996, by

the Office of Pipeline Safety’s Southern Region

Office of an explosion damaging a six-story

building in the Rió Piedras shopping district of

San Juan, Puerto Rico. The Safety Board

dispatched an investigative team from

Washington, D.C., comprising investigative

groups for pipeline operations, survival factors,

and human performance.

Hearing and Depositions

The Safety Board conducted a public

hearing in conjunction with the investigation on

June 2-5, 1997. A staff-conducted deposition

was also conducted on July 1, 1997.

65

	





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79

APPENDIX E

	

	



80

3 2 1 A

E

F

G

Meter Room

D

Elev.

Air Cond.

Handling Eq.

Thermostat

Column cracked

4’ below B/1 level

by west BM

Column cracked 6-7’

Column cracked 2’

below B/1 level

East 1⁄4 of B1-C1 beam

separated 1-2”

1” separation

East 1⁄4 of C1-D1 beam

separated 1 1⁄2-3”

Singed cardboard &

fiberglass samples

taken from B/1 joint

with beam.

C

East 1⁄4 of D1-E1 beam

separated 1⁄2-4”

B/1 floor conn. deflected 4-6” west. Column

cracked several places 3-7 ft. below B/1 level

Wall bowed 6-9” north and severely cracked

Upstairs

Downstairs

Chute Opening in Basement

West BM cracked

column 3’ below

B/1 level

Severe inside

wall cracking

Lower 1/3 of north portion

of wall displaced east 2-3”

Light surface cracking

Column in tact w/surface cracks

East 1⁄4 of E1-F1 beam

separated 1⁄2-2”

4” CI sewer riser in wall

4” CI sewer pipe

at B/1 level

BM cracked column

at 1st fl west side

1’ natural floor drain

Rebars exposed top & bottom of beam

Beam/beam rebars not embedded

Center cracked 1 1⁄2 “ at

bottom w/ no crack at top

- north deflection

Upper 3’ wall cracked &

tilted 6” with wall below

crack moved west 2” at crack

Earth sump

Stairs

B

NOTE: Arrows indicate major

direction of resultant forces
81



	



	



 
	



				
		

 

		

		

	


	


		


 

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83

ABBREVIATIONS

ATF--Bureau of Alcohol, Tobacco and Firearms

CFR--Code of Federal Regulations

CGI--combustible gas indicator

DOT--U.S. Department of Transportation

Enron--Enron Corp.

FEMA--Federal Emergency Management Agency

GIS--Graphical Information System

Heath--Heath Consultants, Inc.

Humberto Vidal--Humberto Vidal, Inc.

LEL--lower explosive limit

MCC--maintenance and construction coordinator

NPRM--Notice of Proposed Rulemaking

O&M Manual--Operations and Maintenance Manual

OPS--Office of Pipeline Safety

PE--polyethylene

PRASA--Puerto Rico Aqueducts and Sewer Authority

PSC--Public Service Commission

PVC--polyvinyl chloride

RSPA--Research and Special Programs Administration

SJGC--San Juan Gas Company