J. R. Lawson, Project Leader

Building and Fire Research Labo

National Institute of Standards and Tec

U.S. Department of Commerce

james.lawson@nist.gov

Federal Building and Fire Safety Inves

of the World Trade Center Disast

Project #8,

Fire Service Technologies and G

June 23, 2004
Contributing Personnel Contributing Personnel

NIST Personnel• J. Randall Lawson• Robert L. Vettori• Schuyler Ruitberg• Lisa Petersen

NIST Experts:

• Vincent Dunn, FDNY (retired) • John J. Hodgens, FDNY (retir• Kevin S. Malley, FDNY (retireNIST Contractor• Nustats, Inc.
Purpose of Project #8 Purpose of Project #8 

To build upon work done by the New York C

(FDNY) and McKinsey & Company by:

1. Fully documenting what happened during 

the fire services to the attacks on the Wo(WTC), up to the time of collapse of WTC 

2. Identify issues that need to be addressed 

practices, standards and codes;

3. Identify alternative practices and/or techn

address these issues; and

4. Identify R&D needs that advance the safe

service in responding to massive fires in 
Technical Approach and Status Technical Approach and Status

This project is divided into four tasks. The fodescription of the tasks:Task 1 - Collect data to document the broad range of 

response operations, command and control fcommunications, and equipment used at the 

collection and review is largely completed.

Task 2 - Interpret the factual analysis to determine the 

successes. Data are being analyzed and cod

Task 3 – Identify alternative emergency response prac

technologies that may advance the safety anfirst responders. A findings based task that i

Task 4 – Report preparation and the identification of R

support of the fire service. Data analysis is in report outline has been drafted, and report d

way.
Interim Report on Emergency Interim Report on Emergency 

Communications Communications 

Principal Objectives:1. To develop a better understanding of the 

emergency communications played durinthe WTC, and 

2. To quantify information related to commu

effectiveness:

• document radio communications rea• quantify radio communications traffic 
Communications Sources Communications Sources

• The Port Authority of New York and New Jersey (PANY

and telephone communications recordings to NIST relatresponse.

• The New York City Police Department (NYPD) provided 

communications recordings for the Special Operations UDivision 1 frequency that were used in operations at the 

• New York City provided NIST with the opportunity to liste

telephone calls made to 9-1-1 Emergency Operators anDispatchers.

• PANYNJ also supplied a recording from the FDNY high-

Authority Police Dept. (PAPD) channel 30 repeater locat

• First person accounts of experiences with radio and tele

communications. 

Note: The FDNY Field Communications truck was not in 

recordings of FDNY radio communications at the site we
First Person [face First Person [face-to-face] Interviews Con

face] Interviews Con

• New York City

FDNY Interviews - 68

Command Officers, Company Officers, FirefighteSquad personnel, EMS, Communications, Fire MNYPD Interviews - 24Command Officers, Special Operations Division OCommunications Personnel, and Aviation Unit Of

• PANYNJ Interviews - 13

PAPD Command Officers, Police Officers, BuildinStaff, Communications & Vertical Transportation 

• Other

Security, Fire Safety, and Communications Perso
• Before the attack at the WTC both landline and ce

systems were working.

• Moments after the first aircraft impacted WTC 1, t

systems were stressed by increased caller volume

• Although there was impact damage and fires were 

WTC towers, some landline telephones were workbuildings.

• After the collapse of WTC 2, a number of cellular 

were not functioning in lower Manhattan.

• After the collapse of WTC 2, there were still some 

telephones working within the city block areas adj

First Person Accounts of Telephon

First Person Accounts of Telephon

Communications Communications 
Radio Communications Analysis Radio Communications Analysis 

Note: Minimum transmission times were typically lesand were often related to keying of a microphone.

Average time per Aver

Dept. transmission before transm

1st aircraft impact and 1st aircr

maximum time max

(s) 

PAPD 3.8 (max. 21.8) 3.3 FDNY 3.8 (max. 50.9) 3.1 NYPD 1.9 (max. 5.9) 3.4 (Div. 1)NYPD No data 5.7 (Special Ops. Div.)
Radio Traffic Volume Radio Traffic Volume 

-

PAPD Channel 26/W

0

102030405060708090

100

0 10 20 30 40

Time (minutes)

Percent Transmissions (%) First Aircraft Impact Second Aircraft Impact

FDNY C

0

102030405060708090

100

0 10 

Percent Transmissions (%) First Aircraft Im

NYPD SOD Channel

0

102030405060708090

100

0 10 20 30 40

Time (minutes)

Percent Transmissions (%) First Aircraft Impact at Zero Time Second Aircraft Impact

T% = 100(Transmissio

NYPD 

0

102030405060708090

100

0 2 4 6 8 

Percent Transmissions (%) First Aircraf
Quality of Radio Communications Quality of Radio Communications 

Some factors that contributed to poor commquality:• background noise, either at the transmissio

receiving point, or both;

• operating health of transmitting and receiv

and antenna systems;

• doubling or crossing of radio signals, caus

multiple transmissions at the same time on radio frequency; and

• radio transmissions may be affected by att

materials or electromagnetic interference.
Radio Communications Readabilit

Radio Communications Readabilit

Readability, is a communications term used 

the ability of a person to hear and understatransmission.Readability Scale:1 – Unreadable2 – Barely readable, occasional words disti3 – Readable with considerable difficulty4 – Readable with practically no difficulty5 – Perfectly readable

Note: This is a subjective scale related to a trained hhear and understand communications transmissionsRef: ARRL (American Radio Relay League) HandboCommunications
Radio Communications Read

Radio Communications Read

PAPD Channel 26/W

2

24%

1

9%

3

43%

4

24%

5

0%

FDNY Ch 

3

42%

4

18%

5

4%

NYPD SOD Channel

2

35%

1

10%

3

32%

4

19%

5

4%

NYPD 

3

32%

4

23%

5

8%
Summary of Readability Re

Summary of Readability Re

Readability 

Dept. 1 2 3 PAPD Ch 26/WPolice Desk 9% 24% 43% FDNY H-R Ch 7(PAPD Ch 30) 10% 26% 42% RepeaterNYPD Div. 1 11% 26% 32% NYPD SOD 10% 35% 32% 
Preliminary Chronology of Emergency C

Preliminary Chronology of Emergency C

Five Chronologies:

1. Dispatch and arrival of emergency res

A chronology of communications providing the times th

responders were dispatched and the times that they ar

2. Evacuation

A record of the evacuation of WTC 1, WTC 2, and the 

3. Emergency response operations

A record of emergency response operations by FDNY, 

4. Emergency response communications

A record of communications, about communications op

5. Condition of the WTC towers

A record of communications concerning the changing c

towers.
Noteworthy Communications Noteworthy Communications

3

26 35

66

121

0 0

6

23 30

0

50

100150200250

8:46 8:48 8:50 9:00 9:15 

time (h:m)

Number of Units 

Dispatched Signal Arriva

Dispatch and Arrival of FDNY Units 
Noteworthy Communications Noteworthy Communications

Evacuation:

• PAPD Police Desk Channel Z: A senior level PAPD 

twice over a two minute period immediately followinimpact for the evacuation of WTC 1. The message Currently, no evidence has been found to suggest twas distributed to personnel responsible for evacua

• 8:59 a.m., PAPD Police Desk Channel Y: A senior 

calls twice for the evacuation of WTC 1 and WTC 2 

WTC complex. The message is acknowledged. At police desk operator broadcasts the message to ev

in the WTC complex. No evidence has be found to information was further distributed to personnel resevacuating the WTC complex.

• Communications data shows that the evacuation pr

always orderly. There were reports of people runni

trains, and there was a report from WTC 5 that “I hacrazy.”
Noteworthy Communications Noteworthy Communications

Evacuation:

• At 9:12 a.m. radio communications to the PAPD po

information on building functions that influenced the process. Information was received from the Fire Cothe lobby of WTC 2 that the Warden phones in the working. The response from the Fire Command DeWardens were to leave the phones.

• Communications from the PAPD police desk docum

physically impaired and elderly people were not abstairs and that they needed assistance to get out of these individuals were on the 51st floor at 9:30 a.m. 

their evacuation attempt is unknown. 
Noteworthy Communications Noteworthy Communications

Emergency Response Operations:• A radio communication at 8:50 a.m. from FDNY Lad

police desk, using a PAPD radio, shows a level of cFDNY and Port Authority personnel.

• NYPD aviation units arrived at the WTC by 8:52 a.m

see if roof rescue was possible and reported back thto land as a result of heavy smoke conditions.

3⁄4 First person interviews with aviation unit personnel also 

the building’s fires was causing the helicopter engine tem

3⁄4 An aviation unit called again at 9:38 a.m. for permission 

WTC 1. A first person interview indicated that the aviatioto assist the people trapped and jumping from the upper indication that landing conditions had improved.

3⁄4 Five minutes after the request to land, a senior NYPD of

one was to rappel onto the buildings.
Noteworthy Communications Noteworthy Communications

Emergency Response Operations:• At 9:18 a.m. a FDNY Chief Officer using the high-rise 

reports that one elevator in WTC 2 is working up to th

communication led to the use of the elevator for taking responders and equipment up into the tower. This elein the shaft and was also being scheduled for the remtime of the building collapse. 

• A radio communication on the FDNY high-rise repeate

a.m. from the FDNY WTC 2 Operations Post located lobby to a Chief FDNY Officer located on the 43rd floo

building states that a NYPD Emergency Service Unit assist. The FDNY Chief Officer gives directions for seto his location. This communication provides an indicNYPD were working together at this level of the opera

• At 9:45 a.m. a radio communication to the PAPD polic

an officer on 22nd floor, can’t release locks on doors, a

loss of electrical power. Interviews and other radio msignificant damage to this floor in WTC 1.
Noteworthy Communications Noteworthy Communications

Emergency Response Communications:• All of the three primary responding departments FD

NYPD experienced radio communications difficultieincident.

• Both PAPD and NYPD had handie-talkies with ope

microphones that produced radio interference. In a

came in from the field indicating that radios were no

• There were many cases where FDNY, PAPD, and 

made radio calls, and they never received an answbe attributed to the failure of the radio system or th

person called to answer. There were cases where 

would answer and would not be heard by the party 

call.
Noteworthy Communications Noteworthy Communications

Emergency Response Communications:• The following examples of radio communications relat

radio traffic, 2) the inability of the radio systems to han

message at a time, and 3) undesirable radio operation

8:49 a.m. - PAPD police desk tells police officers to stay o8:51 a.m. - NYPD dispatcher advises officers that they are 8:53 a.m. - NYPD dispatcher advises that messages are b9:00 a.m. - NYPD dispatcher advises that messages are c9:14 a.m. - PAPD police desk incomplete message from c9:22 a.m. - NYPD dispatcher advises that messages are u9:28 a.m. - PAPD police desk incomplete message from c9:54 a.m. - NYPD dispatcher requests that personnel “kee10:05 a.m. - NYPD dispatcher advises that all units should 10:10 a.m. - NYPD dispatcher advises that 3 units are talk

• At 9:31 a.m. a PAPD officer questions if the red bags 

have been brought to the scene. The answer is no. T

communications between PAPD and FDNY.
Noteworthy Communications Noteworthy Communications

Condition of the WTC Towers:• At 8:47 a.m. and 8:51 a.m. the PAPD police desk rece

indicating that there is a fire on the 22nd floor and there 

the B1 level of WTC 1. These communications providresponders with information concerning the initial rangand threat to the occupants. 

• At 9:36 a.m. a NYC 911 operator receives a telephone 

was a floor collapse in the 90’s of WTC 2. The reportinthat he was now on the 105th floor. At 9:41 a.m. and 9

police dispatcher advises units that the 106th floor is cr

a.m. message appears to be a miscommunication basmessage. 

• At 9:47 a.m. a FDNY firefighter on the 74th floor of WT

rise channel 7 that there is no smoke or fire on the floothe stairway walls were breached on 68, 73, and 74th f
Noteworthy Communications Noteworthy Communications

Condition of the WTC Towers:• The following communications from the NYPD aviatio

critical information concerning the impending collapse These communications describe the degrading buildin

they relate to the safety of individuals inside and arou

9:49 a.m. - NYPD aviation unit reports “large pieces” fa

9:58 a.m. - NYPD aviation unit advises WTC 2 is collap10:06 a.m. - NYPD police officer advises that it will not 

before WTC 1 comes down.

10:20 a.m. - NYPD aviation unit reports that WTC 1 mig

10:21 a.m. - NYPD aviation unit reports southwest corn

buckling

10:27 a.m. - NYPD aviation unit reports WTC 1 roof wil

shortly 

10:28 a.m. - NYPD police officer reports that WTC 1 is 
1. After the first aircraft struck WTC 1, there was an 

of 5 peak increase in traffic level over the norma

responder radio communications, followed by an of 3 steady increase in the level of subsequent tr

2. A surge in communications traffic volume made i

handle the flow of communications and delivery 

3. Analysis of radio communications records indicat

to 1/2 of the radio messages during surge conditcomplete nor understandable.

4. Preliminary analysis of the FDNY City-wide, high

(PAPD channel 30) recording indicated that the W

was operating.

Findings Findings
5. Communications records and interviews indicate t

conditions on the top of the two WTC buildings prehelicopters from conducting safe roof evacuation o

6. NYPD aviation unit personnel reported critical info

impending collapse of the WTC towers several mi

collapse. No evidence has been found to suggest information was further communicated to all emer

at the scene. 

Findings Continued Findings Continued
Questions? Questions?