U.S. Fire Administration/Technical Report Series

Highrise Office 

Building Fire 

One Meridian Plaza

Philadelphia, Pennsylvania

USFA-TR-049/February 1991

U.S. Fire Administration Fire Investigations Program

T

he U.S. Fire Administration develops reports on selected major fires throughout the country. 

The fires usually involve multiple deaths or a large loss of property. But the primary criterion 

for deciding to do a report is whether it will result in significant “lessons learned.” In some 

cases these lessons bring to light new knowledge about fire--the effect of building construction or 

contents, human behavior in fire, etc. In other cases, the lessons are not new but are serious enough 

to highlight once again, with yet another fire tragedy report. In some cases, special reports are developed to discuss events, drills, or new technologies which are of interest to the fire service.

The reports are sent to fire magazines and are distributed at National and Regional fire meetings. The 

International Association of Fire Chiefs assists the USFA in disseminating the findings throughout the 

fire service. On a continuing basis the reports are available on request from the USFA; announcements of their availability are published widely in fire journals and newsletters.

This body of work provides detailed information on the nature of the fire problem for policymakers 

who must decide on allocations of resources between fire and other pressing problems, and within 

the fire service to improve codes and code enforcement, training, public fire education, building 

technology, and other related areas.

The Fire Administration, which has no regulatory authority, sends an experienced fire investigator 

into a community after a major incident only after having conferred with the local fire authorities 

to insure that the assistance and presence of the USFA would be supportive and would in no way 

interfere with any review of the incident they are themselves conducting. The intent is not to arrive 

during the event or even immediately after, but rather after the dust settles, so that a complete and 

objective review of all the important aspects of the incident can be made. Local authorities review 

the USFA’s report while it is in draft. The USFA investigator or team is available to local authorities 

should they wish to request technical assistance for their own investigation.

This report and its recommendations were developed by USFA staff and by TriData Corporation, 

Arlington, Virginia, its staff and consultants, who are under contract to assist the USFA in carrying 

out the Fire Reports Program.

The USFA greatly appreciates the cooperation received from the Philadelphia Fire Department. 

In particular, the assistance and information provided by Fire Commissioner Roger Ulshafer 

(ret.), Commissioner Harold Hairston, Deputy Commissioner Christian Scheizer (ret.), Deputy 

Commissioner Phil McLaughlin, Deputy Commissioner Matthew J. McCrory Jr., Battalion Chief 

Theodore Bateman, Battalion Chief Richard Bailey, and Lieutenant Matthew Medley were invaluable. 

For additional copies of this report write to the U.S. Fire Administration, 16825 South Seton Avenue, 

Emmitsburg, Maryland 21727. The report is available on the USFA Web site at http://www.usfa.dhs.gov/

Highrise Office Building Fire

One Meridian Plaza

Philadelphia, Pennsylvania

Report by: J. Gordon Routley

Charles Jennings

Mark Chubb

This is Report 049 of the Major Fires Investigation Project conducted

by TriData Corporation under contract EMW-90-C-3338 to the United

States Fire Administration, Federal Emergency Management Agency.

Department of Homeland Security

United States Fire Administration

National Fire Data Center

U.S. Fire Administration

Mission Statement

As an entity of the Federal Emergency 

Management Agency (FEMA), the mission 

of the U.S. Fire Administration (USFA) is to 

reduce life and economic losses due to fire 

and related emergencies, through leadership, advocacy, coordination, and support. We 

serve the Nation independently, in coordination with other Federal agencies, and in partnership with fire protection and emergency 

service communities. With a commitment to 

excellence, we provide public education, training, technology, and data initiatives.

Foreword

This report on the Philadelphia, Pennsylvania, One Meridian Plaza fire documents one of the most 

significant highrise fires in United States’ history. The fire claimed the lives of three Philadelphia 

firefighters and gutted eight floors of a 38-story fire-resistive building causing an estimated $100 

million in direct property loss and an equal or greater loss through business interruption. Litigation 

resulting from the fire amounts to an estimated $4 billion in civil damage claims. Twenty months 

after the fire this building, one of Philadelphia’s tallest, situated on Penn Square directly across from 

City Hall, still stood unoccupied and fire-scarred, its structural integrity in question.

This fire is a large scale realization of fire risks that have been identified on many previous occasions. 

The most significant new information from this fire relates to the vulnerability of the systems that 

were installed to provide electrical power and to support fire suppression efforts. In this incident 

there was an early loss of normal electrical power, a failure of the emergency generator and a major 

problem with the standpipe system, each of which contributed to the final outcome. These experiences should cause responsible individuals and agencies to critically re-examine the adequacy of all 

emergency systems in major buildings.

When the initial news reports of this fire emerged, attention focused on how a modem, fire-resistive 

highrise in a major metropolitan city with a well-staffed, well-equipped fire department could be 

so heavily damaged by fire. The answer is rather simple -- fire departments alone cannot expect or 

be expected to provide the level of fire protection that modern highrises demand. The protection 

must be built-in. This fire was finally stopped when it reached a floor where automatic sprinklers 

had been installed.

This report will demonstrate that the magnitude of this loss is greater than the sum of the individual 

problems and failures which produced it. Although problems with emergency power systems, standpipe pressure reducing valves, fire alarm systems, exterior fire spread, and building staff response can 

be identified, the magnitude of this fire was a result of the manner in which these factors interacted 

with each other. It was the combination of all of these factors that produced the outcome.

At the time of the One Meridian Plaza fire, the three model fire prevention codes had already adopted 

recommendations or requirements for abating hazards in existing highrise buildings. Each of the 

model building codes contains explicit requirements for fire protection and means of egress in 

highrise buildings. Actions were and are underway in many cities and several States to require retrofitting of existing highrise buildings with automatic sprinkler systems, fire detection and alarm 

systems, and other safety provisions. Since the Meridian Plaza fire, the National Fire Protection 

Association’s Technical Committee on Standpipe Systems has proposed a complete revision of NFPA 

14, Standard for Installation of Standpipe and Hose Systems. The new version of NFPA 14 was approved by the 

NFPA membership at the 1992 fall meeting in Dallas, Texas. All of these efforts are necessary and 

commendable. To prove successful, however, they must take a comprehensive, holistic approach to 

the problem of highrise fire safety, if we are to keep One Meridian Plaza from being surpassed by yet 

another devastating fire.

TaBle OF COnTenTs

OVERVIEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

SUMMARY OF KEY ISSUES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

THE BUILDING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Stairways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Elevators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Heating, Ventilation, and Air Conditioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Plumbing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Electrical and Communications Risers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Emergency Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

FIRE PROTECTION SYSTEMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Fire Detection and Alarm Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Standpipes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Automatic Sprinklers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

THE FIRE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Delayed Report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Initial Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Electrical Power Failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Initial Attack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Fire Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Water Supply Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Three Firefighters Lost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Continuing Efforts to Improve Water Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Firefighting Operations Suspended. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Fire Stopped. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

ANALYSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Smoke Movement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Fuel Loading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Structural Conditions Observed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

INCIDENT COMMAND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Communications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Logistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

continued on next page
BUILDING AND FIRE REGULATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

FIRE CODE ENFORCEMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

LESSONS LEARNED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

CONCLUSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

SOURCES OF INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Appendix A: Elevation Drawing of the Building and 22nd Floor Plan, Floor of Origin. . . . . 27

Appendix B: Building Emergency Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Appendix C: Philadelphia Fire DepartmentHighrise Emergency Procedures. . . . . . . . . . . . . 30

Appendix D: Factory Mutual Engineering CorporationPressure Reducing Valve Loss 

Prevention Data Sheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Appendix E: Philadelphia Fire DepartmentPressure Regulating Device Fact Sheet. . . . . . . . . 39

Appendix F: Philadelphia Fire Department Block Inspection Program. . . . . . . . . . . . . . . . . 47

Appendix G: Philadelphia Fire Code Amendments Adopted after the One Meridian 

Plaza Fire. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Appendix H: Photographs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Table of Contents (continued)
1

Highrise Office Building Fire

One Meridian Plaza

Philadelphia, Pennsylvania

February 23, 1991

Local Contacts: Commissioner (ret.) Roger Ulshafer

Commissioner Harold Hairston

Deputy Commissioner (ret.) Christian Schweizer

Deputy Commissioner Phil McLaughlin

Deputy Commissioner Matthew J. McCrory, Jr.

Theodore Bateman, Battalion Chief

Richard Bailey, Battalion Chief

Matthew Medley, Lieutenant

City of Philadelphia Fire Department

240 Spring Garden Street

Philadelphia, Pennsylvania 19123-2991

(215) 592-5962

O

A fire on the 22nd floor of the 38-story Meridian Bank Building, also known as One Meridian Plaza, 

was reported to the Philadelphia Fire Department on February 23, 1991 at approximately 2040 

hours and burned for more than 19 hours. The fire caused three firefighter fatalities and injuries to 

24 firefighters. The 12-alarms brought 51 engine companies, 15 ladder companies, 11 specialized 

units, and over 300 firefighters to the scene. It was the largest highrise office building fire in modern 

American history -- completely consuming eight floors of the building -- and was controlled only 

when it reached a floor that was protected by automatic sprinklers. A table summarizing the key 

aspects of the fire is presented on the following pages.

The fire department arrived to find a well-developed fire on the 22nd floor, with fire dropping down 

to the 21st floor through a set of convenience stairs. (For an elevation drawing of the building and 

the 22nd floor plan see Appendix A.) Heavy smoke had already entered the stairways and the floors 

immediately above the 22nd. Fire attack was hampered by a complete failure of the building’s electrical system and by inadequate water pressure, caused in part by improperly set pressure reducing 

valves on standpipe hose outlets.
2 U.S. Fire Administration/Technical Report Series

SUMMArY oF KeY ISSUeS

Issues Comments

Origin and Cause The fire started in a vacant 22nd floor office in a pile of linseed oil-soaked rags left by a contractor.

Fire Alarm System The activation of a smoke detector on the 22nd floor was the first notice of a possible fire. Due 

to incomplete detector coverage, the fire was already well advanced before the detector was 

activated.

Building Staff Response Building employees did not call the fire department when the alarm was activated. An employee 

investigating the alarm was trapped when the elevator opened on the fire floor and was rescued 

when personnel on the ground level activated the manual recall. The fire department was not 

called until the employee had been rescued.

Alarm Monitoring Service The private service which monitors the fire alarm system did not call the fire department when the 

alarm was first activated. A call was made to the building to verify that they were aware of the 

alarm. The building personnel were already checking the alarm at that time.

Electrical Systems Installation of the primary and secondary electrical power risers in a common unprotected enclosure resulted in a complete power failure when the fire damaged conductors shorted to ground. 

The natural gas powered emergency generator also failed.

Fire Barriers Unprotected penetrations in fire-resistance rated assemblies and the absence of fire dampers in 

ventilation shafts permitted fire and smoke to spread vertically and horizontally.

Ventilation openings in the stairway enclosures permitted smoke to migrate into the stairways, 

complicating firefighting.

Unprotected openings in the enclosure walls of 22nd floor electrical closet permitted the fire to 

impinge on the primary and secondary electrical power risers.

Standpipe System and 

Pressure Reducing Valves 

(PRVs)

Improperly installed standpipe valves provided inadequate pressure for fire department hose 

streams using 1-3/4-inch hose and automatic fog nozzles. Pressure reducing valves were 

installed to limit standpipe outlet discharge pressures to safe levels. The PRVs were set too low 

to produce effective hose streams; tools and expertise to adjust the valve settings did not become 

available until too late.

Locked Stairway Doors For security reasons, stairway doors were locked to prevent reentry except on designated floors. 

(A building code variance had been granted to approve this arrangement.) This compelled firefighters to use forcible entry tactics to gain access from stairways to floor areas.

Fire Department Pre-Fire 

Planning

Only limited pre-fire plan information was available to the Incident Commander. Building owners 

provided detailed plans as the fire progressed.

Firefighter Fatalities Three firefighters from Engine Company 11 died on the 28th Floor when they became disoriented 

and ran out of air in their SCBAs.

Exterior Fire Spread 

“Autoexposure”

Exterior vertical fire spread resulted when exterior windows failed. This was a primary means of 

fire spread.

Structural Failures Fire-resistance rated construction features, particularly floor-ceiling assemblies and shaft enclosures (including stair shafts), failed when exposed to continuous fire of unusual intensity and 

duration.

Interior Fire Suppression 

Abandoned

After more than 11 hours of uncontrolled fire growth and spread, interior firefighting efforts were 

abandoned due to the risk of structural collapse.

Automatic Sprinklers The fire was eventually stopped when it reached the fully sprinklered 30th floor. Ten sprinkler 

heads activated at different points of fire penetration.
USFA-TR-049/February 1991 3

The three firefighters who died were attempting to ventilate the center stair tower. They radioed a 

request for help stating that they were on the 30th floor. After extensive search and rescue efforts, 

their bodies were later found on the 28th floor. They had exhausted all of their air supply and could 

not escape to reach fresh air. At the time of their deaths, the 28th floor was not burning but had an 

extremely heavy smoke condition.

After the loss of three personnel, hours of unsuccessful attack on the fire, with several floors simultaneously involved in fire, and a risk of structural collapse, the Incident Commander withdrew all 

personnel from the building due to the uncontrollable risk factors. The fire ultimately spread up to 

the 30th floor where it was stopped by ten automatic sprinklers.

THe BUIlDInG

One Meridian Plaza is a 38-story highrise office building, located at the corner of 15th Street and 

South Penn Square in the heart of downtown Philadelphia, in an area of highrise and mid-rise 

structures. On the east side, the building is attached to the 34-story Girard Trust Building and it is 

surrounded by several other highrise buildings. The front of the building faces City Hall.

One Meridian Plaza has three underground levels, 36 above ground occupiable floors, two mechanical floors (12 and 38), and two rooftop helipads. The building is rectangular in shape, approximately 

243 feet in length by 92 feet in width (approximately 22,400 gross square feet), with roughly 

17,000 net usable square feet per floor. (See Appendix A for floor plan.) Site work for construction 

began in 1968, and the building was completed and approved for occupancy in 1973.

Construction was classified by the Philadelphia Department of Licenses and Inspections as equivalent 

to BOCA Type 1B construction which requires 3-hour fire rated building columns, 2-hour fire rated 

horizontal beams and floor/ceiling systems, and 1-hour fire rated corridors and tenant separations. 

Shafts, including stairways, are required to be 2- hour fire rated construction, and roofs must have 

1-hour fire rated assemblies.

The building frame is structural steel with concrete floors poured over metal decks. All structural 

steel and floor assemblies were protected with spray-on fireproofing material. The exterior of the 

building was covered by granite curtain wall panels with glass windows attached to the perimeter 

floor girders and spandrels.

The building utilizes a central core design, although one side of the core is adjacent to the south 

exterior wall. The core area is approximately 38 feet wide by 124 feet long and contains two stairways, four banks of elevators, two HVAC supply duct shafts, bathroom utility chases, and telephone 

and electrical risers.

Stairways

The building has three enclosed stairways of concrete masonry construction. Each stairway services 

all 38 floors. The locations of the two stairways within the building core shift horizontally three 

or four times between the ground and the 38th floor to accommodate elevator shafts and machine 

rooms for the four elevator banks. Both of these stairways are equipped with standpipe risers.

Adjacent to the stairway enclosures are separate utility and HVAC shafts. There are pipe and duct penetrations through the shaft and stairway enclosure walls. The penetrations are unprotected around 

the sleeved pipes and fire dampers are not installed in HVAC ducts penetrating the fire-resistance 
4 U.S. Fire Administration/Technical Report Series

rated wall assemblies. This effectively creates many openings between the utility shafts, and the 

individual floors, primarily in the plenum area above the ceilings, as well as between the shafts and 

the stairway enclosures.

The third enclosed stairway is located at the east end of the building. This stairway attaches the floors 

of the Meridian Plaza to the corresponding floors of the Girard Trust Building. Adjacent to the east 

stairway is an additional enclosed utility shaft which also has pipe and duct penetrations through 

the shaft enclosure walls. There are no fire or smoke barriers around the sleeved pipes and no fire 

dampers in the HVAC ducts that penetrate the shaft walls.

Elevators

Elevator service is provided by four zoned elevator banks identified as A through D. Elevator 

Bank A serves floors 2-11. Elevator Bank B has two shafts which enclose seven elevators: six are 

passenger elevators that serve floors 12-21, and one is a freight elevator that serves floors 22-38. 

Elevator Bank C serves floors 21-29, and Elevator Bank D serves floors 29-37. The elevator shafts 

are constructed of concrete and masonry and extend from the first floor or lower levels to the 

highest floor served by the individual elevator banks. At the top of each elevator bank is the associated elevator equipment room.

The elevator shafts that serve the upper floors are express rise and do not have openings to the lower 

floors. Only the Bank C passenger elevators and the freight elevator served the fire floors. The elevator shafts did not appear to play a significant role in the spread of combustion products.

Each elevator lobby is equipped with a smoke detector that, when activated, recalls the elevator cars 

to the first floor lobby. Firefighter’s service (elevator recall) features were added in 1981 under 

provisions of the State Elevator Code.1

 Occupant use of elevators in emergencies is addressed in the 

Building Emergency Instructions shown in Appendix B. 

Heating, Ventilation, and Air Conditioning

The heating, ventilation, and air conditioning (HVAC) system is composed of four air handling 

systems. Two systems are located in the 38th floor mechanical room and service the east and west 

halves of the upper floors. The other two systems are located in the 12th floor mechanical room and 

service the east and west halves of the lower floors. Each system supplies air to its respective floors 

through one or two supply air shafts located within the building core and receives return air from its 

associated return air shafts. Return air shafts are located at each of the four building corners. Upon 

examination at selected locations, the HVAC supply and return air shafts did not appear to have fire 

dampers at the duct penetrations on each floor.

Plumbing

The bathroom utility piping extends through the 38 floors through pipe chases that are formed 

by the space between two walls. These pipe chases transfer location as the bathroom locations 

change floor to floor. Upon a sample examination of the pipe chases, it was found that floor 

penetrations were not closed or sealed to maintain the integrity of the fire- resistance rated floor/

ceiling assemblies.

1 In Pennsylvania, elevators are regulated through the State Department of Labor and Industry.
USFA-TR-049/February 1991 5

Electrical and Communications Risers

The electrical and telephone risers are enclosed in separate rooms on each floor. The rooms are 

located directly above one another and are intended to function as vertical shafts, with rated separations required at horizontal penetrations from the shafts into floor and ceiling spaces at each level. 

Within the telephone and electrical rooms, unprotected penetrations of the floor assemblies allow 

conduits and exposed wires to travel from floor to floor. Several breaches of fire-resistance rated 

construction were observed in the walls separating the electrical and telephone rooms from the ceiling plenums and occupied spaces on each floor.

Emergency Power

The building electrical system receives power from two separate electrical substations and is backed-up 

by an emergency generator. The two sources of power are arranged so that the load would automatically transfer to the second source upon failure of the first. Electrical power for One Meridian Plaza 

and four adjacent buildings is distributed from the basement of 1414 S. Penn Square.

The electric service enters the building via the basement from the adjoining building and is distributed to the 12th and 38th floor mechanical rooms via the electrical risers in the building core. From 

the 12th and 38th floor mechanical rooms, electrical power is distributed to the major mechanical 

systems and to a buss bar riser, which services distribution panels on the individual floors.

Emergency power was provided by a 340 kw natural gas-fired generator located in the 12th floor 

mechanical room. The generator was sized to supply power for emergency lighting and the fire 

alarm system, the fire pump located on the 12th floor and one car in each bank of elevators. The generator’s fuel was supplied by the building’s natural gas service. This generator was not required by 

the building code, since the building’s electrical power was supplied by two separate substations.

The generator was reported to have been tested weekly. The last recorded test date was January 

30, almost four weeks before the fire, and the maintenance records indicate that problems were 

encountered during engine start-up under load conditions at that time. During a detailed inspection 

following that test, a damaged part was discovered and replaced. After the repair, the generator was 

started without a load and appeared to work properly, but no subsequent tests were performed to 

determine if the problems persisted under load conditions.

Records of earlier maintenance and test activity suggest that load tests were performed only occasionally. Test and maintenance records indicate a long history of maintenance problems with the 

emergency generator system. Many of these problems became manifest during or immediately after 

conducting tests under load.

FIRe PROTeCTIOn sYsTeMs

At the time of construction, the Philadelphia Building Code required only a local fire alarm system 

with manual stations at each exit and smoke detectors in the supply and return air shafts. Hose 

stations supplied from the domestic water service and portable fire extinguishers were required 

for occupant use. Dry standpipes were installed for fire department use. Below ground levels were 

required to be provided with automatic sprinklers.

As a result of local code changes, several improvements to the fire protection systems were made in 

the years following the building’s construction.
6 U.S. Fire Administration/Technical Report Series

In 1981, the Philadelphia Department of Licenses and Inspections implemented amendments to 

the fire code which were intended to address the life safety of highrise building occupants. These 

requirements included installation of stair identification signs, provisions to permit stairway reentry, and installation of smoke detection in common areas in the path of access to exits. The 

“common areas” provision of the code was intended to address corridors and exit passageways in 

multi-tenant floors. The smoke detector requirements were interpreted in such a way that single 

tenant “open plan” floors were only required to have detectors installed at the exits; the entire floor, 

although open, was not considered a “common area.”. Smoke detectors were also installed in the 

return air plenum adjacent to the return air shaft intakes in each corner of the building. These provisions required that building owners file permits for this work within one year of the code change. 

City records do not indicate when this work was performed in this particular building or if it was 

inspected and approved.

Fire Detection and Alarm Systems

At the time of construction, One Meridian Plaza was equipped with a coded manual fire alarm 

system with pull stations installed adjacent to each of the three exit stairwells on each floor. Smoke 

detection was provided in the major supply and return air ducts at the mechanical floor levels.

After the 1981 fire code amendments were enacted, the hardware on stairway doors was required to 

allow access from stairs back to floor areas or to be unlocked automatically in the event that the fire 

alarm was activated. One Meridian Plaza was granted a variance from this provision and generally 

had unlocked doors every three floors.

Approximately one and a half years before the fire, a public address system was installed throughout 

the building. This system was operable from the lobby desk and had the capability of addressing 

floors, stairways, elevator machine rooms, and elevators. Two-way communication was possible 

with elevators and elevator machine rooms.

As additional devices and systems were installed, they were connected to the fire alarm system to 

sound through the single-stroke bells originally installed with the manual fire alarm system. Smoke 

detector and water flow signals were assigned their own codes to allow annunciation not only at the 

lobby but throughout the building for those members of the building staff who knew the codes.

Standpipes

The occupant use standpipe system, which was connected to the domestic water supply, provided 

two outlets per floor with 100 feet of 1-1/2-inch hose and a nozzle. The hose cabinets were located 

in corridors on each floor.

A dry standpipe system was originally installed with 6 inch risers in the west and center stair towers 

and outlets for 2-1/2 fire department hoselines at each floor level. This system was converted to a 

wet riser system in 1988, to supply automatic sprinklers on some of the upper floors. An 8 inch 

water supply was provided to deliver water to two 750 gpm electric fire pumps, one in the basement 

and one on the 12th floor.

The basement pump supplied the lower standpipe zone (floors B-12) while the 12th floor pump 

served the upper zone (floors 13-38).

There was no standpipe in the east stair tower.
USFA-TR-049/February 1991 7

A November 1988 Board of Building Standards decision permitted both zones to be served by a 

common fire department connection, as part of a plan that would provide for the installation of 

automatic sprinklers on all floors by November 1993.2

Due to the height of the zones and the installation of fire pumps, pressures exceeded the 100 psi 

limit permitted by NFPA 14, Installation of Standpipe and Hose Systems at the standpipe hose outlets on 

several lower floors in each zone. Pressure restricting devices, which limit the discharge through 

standpipe outlets by restricting the orifice, were installed on the mezzanine and second floor levels 

and on floors 26 through 30. Pressure reducing valves, which regulate both static pressure and discharge pressure under variable flow conditions, were installed on floors 13 through 25.

Both types of devices prevent dangerous discharge pressures from hose outlets at the lower floors of 

each standpipe zone. The Philadelphia Fire Department investigators report that the plans submitted 

at the time the standpipes were converted did not indicate that PRVs were to be installed.

Automatic Sprinklers

Only the service floors located below grade were protected by automatic sprinklers at the time of 

construction. Conversion of the dry standpipe to a wet system with fire pumps facilitated the installation of automatic sprinklers throughout the building. At the request of selected tenants, sprinklers 

were installed on several floors during renovations, including all of the 30th, 31st, 34th, and 35th 

floors, and parts of floors 11 and 15. Limited service sprinklers, connected to the domestic water 

supply system, were installed in part of the 37th floor. The building owners had plans to install 

sprinklers on additional floors as they were renovated.

THe FIre

Delayed Report

At approximately 2023 hours on February 23, 1991, a smoke detector was activated on the 22nd 

floor of the One Meridian Plaza building. The activated detector is believed to have been located at 

the entrance to the return air shaft in the northeast corner of the building. At that time there were 

three people in the building, an engineer and two security guards.3

 The alarm sounded throughout 

the building and elevator cars automatically returned to the lobby. The building engineer investigated the alarm using an elevator on manual control to go to the 22nd floor. The central station 

monitoring company that served the building reportedly called the guard desk in the lobby to report 

the alarm. The call came in before the engineer reached the fire floor, and the alarm company was 

told that the source of the alarm was being investigated. The alarm company did not notify the fire 

department at that time.

When the elevator doors opened at the 22nd floor, the engineer encountered heavy smoke and heat. 

Unable to reach the buttons or to leave the elevator car to seek an exit, the building engineer became 

trapped. He was able to use his portable radio to call the security guard at the lobby desk requesting 

2 Philadelphia Fire Department, “Investigative Report,” Section M, p. 2.

3

The building staff regulated the after-hours population of the building through a lighting request system where tenants 

lights would be turned on for the duration of their work. In addition, there was a security system in the building that 

recorded any passage through stairwell doors.
8 U.S. Fire Administration/Technical Report Series

assistance. Following the trapped engineer’s instructions, the security guard in the lobby recalled the 

elevator to the ground floor using the Phase II firefighter’s safety feature.

The second security guard monitored the radio transmissions while taking a break on the 30th floor. 

This guard initially mistook the fire alarm for a security alarm believing that he had activated a tenant’s security system while making his rounds. He evacuated the building via the stairs when he 

heard the building engineer confirm there was a fire on the 22nd floor.

The roving guard reported that as he descended from the 30th floor the stairway was filling with 

smoke. He reached the ground level and met the engineer and the other security guard on the street 

in front of the building.

The Philadelphia Fire Department report on the incident states that the lobby guard called the alarm 

monitoring service to confirm that there was an actual fire in the building when the engineer radioed to her from the 22nd floor. After meeting outside and accounting for each other’s whereabouts 

the three building personnel realized that they had not yet called the fire department.

The first call received by the Philadelphia Fire Department came from a passerby who used a pay 

telephone near the building to call 9-1-1. The caller reported smoke coming from a large building 

but was unable to provide the exact address. While this call was still in progress, at approximately 

2027 hours, a call was received from the alarm monitoring service reporting a fire alarm at One 

Meridian Plaza.

Initial Response

The Philadelphia Fire Department dispatched the first alarm at 2027 hours consisting of four engine 

and two ladder companies with two battalion chiefs. The first arriving unit, Engine 43, reported 

heavy smoke with fire showing from one window at approximately the mid-section of the building 

at 2031 hours. A security guard told the first arriving battalion chief that the fire was on the 22nd 

floor. Battalion Chief 5 ordered a second alarm at 2033 hours.

While one battalion chief assumed command of the incident at the lobby level, the other battalion chief organized an attack team to go up to the fire floor. (The Philadelphia Fire Department’s 

“Highrise Emergency Procedures” Operation Procedure 33 is presented in Appendix C.) The battalion chief directed the attack team to take the low-rise elevators up the 11th floor and walk up 

from there.

Electrical Power Failure

Shortly after the battalion chief and the attack team reached the 11th floor there was a total loss of 

electrical power in the building. This resulted when intense heat from the fire floor penetrated the 

electrical room enclosure. The heat caused the cable insulation to melt resulting in a dead short 

between the conductor and the conduit in both the primary and secondary power feeds, and the loss 

of both commercial power sources. The emergency generator should have activated automatically, 

but it failed to produce electric power. These events left the entire building without electricity for the 

duration of the incident in spite of several efforts to restore commercial power and to obtain power 

from the generator.

This total power failure had a major impact on the firefighting operations. The lack of lighting 

made it necessary for firefighters to carry out suppression operations in complete darkness using 
USFA-TR-049/February 1991 9

only battery powered lights. Since there was no power to operate elevators, firefighters were 

forced to hand carry all suppression equipment including SCBA replacement cylinders up the 

stairs to the staging area that was established on the 20th floor. In addition, personnel had to 

climb at least 20 floors to relieve fellow firefighters and attack crews increasing the time required 

for relief forces to arrive. This was a problem for the duration of the incident as each relief crew 

was already tired from the long climb before they could take over suppression duties from the 

crews that were previously committed.

Initial Attack

As the initial attack crews made their way toward the 22nd floor they began to encounter smoke in 

the stairway. At the 22nd floor they found the west stair tower door locked. The door was already 

warped and blistering from the heat, and heavy fire could be seen through the door’s wire glass 

window. A 1-3/4-inch handline was stretched up the stairway from a standpipe connection on 

the floor below and operated through the window while a ladder company worked on forcing 

open the door.

It took several minutes before the door could be forced open and an attempt could be made to 

advance onto the fire floor with the 1-3/4-inch attack line. The crews were not able to penetrate 

onto the 22nd floor due to the intense heat and low water pressure they were able to obtain from 

their hoseline.

An entry was also made on the 21st floor where the firefighters were able to see fire on the floor 

above through the open convenience stair. They attempted to use an occupant hoseline to attack the 

fire but could not obtain water from that outlet. They then connected a 1-3/4 inch attack line to the 

standpipe outlet in the stairway, but they could not obtain sufficient pressure to attack the flames. A 

Tactical Command Post was established on the 21st floor and a staging area was set up on floor 20.

Fire Development

By this time fire was visible from several windows on the 22nd floor and crews outside were evacuating the area around the building and hooking up supply lines to the building’s standpipe connections. As flames broke through several more windows around a major portion of the fire floor, the 

floor above was subject to autoexposure from flames lapping up the side of the building. Additional 

alarms were called to bring personnel and equipment to the scene for a large scale fire suppression 

operation.

As the fire developed on the 22nd floor, smoke, heat, and toxic gases began moving through the 

building. Vertical fire extension resulted from unprotected openings in floor and shaft assemblies, 

failure of fire-resistance rated floor assemblies, and the lapping of flames through windows on the 

outside of the building.

Water Supply Problems

The normal attack hoselines used by the Philadelphia Fire Department incorporate 1-3/4-inch hoselines with automatic fog nozzles designed to provide variable gallonage at 100 psi nozzle pressure. 

The pressure reducing valves in the standpipe outlets provided less than 60 psi discharge pressure, 

which was insufficient to develop effective fire streams. The pressure reducing values (PRVs) were 

field adjustable using a special tool. However, not until several hours into the fire did a technician 
10 U.S. Fire Administration/Technical Report Series

knowledgeable in the adjustment technique arrive at the fire scene and adjust the pressure on several 

of the PRVs in the stairways.

When the PRVs were originally installed, the pressure settings were improperly adjusted. Index values marked on the valves did not correspond directly to discharge pressures. To perform adjustments 

the factory and field personnel had to refer to tables in printed installation instructions to determine 

the proper setting for each floor level.4

 For more detailed information about PRVs see Appendices D 

and E.

Several fire department pumpers were connected to the fire department connections to the standpipe 

system in an attempt to increase the water pressure. The improperly set PRVs effectively prevented 

the increased pressure in the standpipes from being discharged through the valves. The limited 

water supply prevented significant progress in fighting the fire and limited interior forces to operating from defensive positions in the stairwells. During the next hour the fire spread to the 23rd and 

24th floors primarily through autoexposure, while firefighters were unable to make entry onto these 

floors due to deteriorating heat and smoke conditions and the lack of water pressure in their hoselines. Windows on the 22nd floor broke out and the 23rd and 24th floor windows were subject to 

autoexposure from flames lapping up the sides of the building.

On the street below pedestrians were cleared from the area because of falling glass and debris as 

more and more windows were broken out by the fire. Additional hoselines were connected to the 

standpipe connections, attempting to boost the water pressure in the system. However, the design 

of the PRVs did not allow the higher pressures to reach the interior hose streams. Additional alarms 

were requested to bring a five-alarm assignment to the scene.

Three Firefighters Lost

As firefighters attempted to make entry to the burning floors from the stairways, heavy smoke continued to build up within the stair shafts and banked down from the upper floors. An engine company was assigned to attempt to open a door or hatch to ventilate the stairways at the roof level to 

allow the smoke and heat to escape. A captain and two firefighters from Engine 11 started up the 

center stair from the 22nd floor with this assignment. Engine 11 subsequently radioed that they 

had left the stairway and were disoriented in heavy smoke on the 30th floor. Attempts were made to 

direct the crew by radio to one of the other stairways.

Shortly thereafter a radio message was received at the Command Post from Engine 11’s Captain 

requesting permission to break a window for ventilation. This was followed moments later by a 

message from a crew member of Engine 11 reporting that “the captain is down.” Approval was given 

to break the window and rescue efforts were initiated to search for the crew. Search teams were sent 

from below and a helicopter was requested to land a team on the roof. The search teams were able 

to reach the 30th floor, which was enveloped in heavy smoke, but were unable to find the missing 

firefighters. They then searched the floors above without success. An eight member search team 

became disoriented and ran out of air in the mechanical area on the 38th floor, while trying to find 

an exit to the roof. They were rescued by the team that had landed on the roof and were transported 

back to ground level by the helicopter.

4

The pressure reducing valves in the vicinity of the fire floor (floors 18 through 20) were set at “80” on the valve index 

which corresponded to a discharge pressure between 55 and 57 psi, depending on the elevation. This would provide a 

nozzle pressure of 40 to 45 psi at the end of a 150- to 200-foot hoseline.
USFA-TR-049/February 1991 11

Several attempts were made to continue the search, until helicopter operations on the rooftop had 

to be suspended due to the poor visibility and the thermal drafts caused by the heat of the fire. The 

helicopter crew then attempted an exterior search, using the helicopter’s searchlight, and at 0117 

located a broken window on the southeast corner of the 28th floor, in an area that could not be seen 

from any of the surrounding streets. Another rescue team was assembled and finally located the 

three missing members just inside the broken window on the 28th floor at approximately 0215. At 

that time the fire was burning on the 24th and 25th floors and extending to the 26th.

The victims were removed to the Medical Triage Area on the 20th floor, but resuscitation efforts were 

unsuccessful and they were pronounced dead at the scene. An estimated three to four hours had elapsed 

since they had reported that they were in trouble and all had succumbed to smoke inhalation.5

The three deceased members of Engine Company 11 were Captain David P. Holcombe (age 52), 

Firefighter Phyllis McAllister (43), and Firefighter James A. Chappell (29).

Prior to being assigned to this task, the crew had walked up to the fire area wearing their full protective clothing and SCBA and carrying extra equipment. It is believed that they started out with 

full SCBA cylinders, but it is not known if they became disoriented from the heavy smoke in the 

stairway, encountered trouble with heat build-up, or were exhausted by the effort of climbing 28 

floors. Some combination of these factors could have caused their predicament. Unfortunately, even 

after breaking the window they did not find relief from the smoke conditions which were extremely 

heavy in that part of the building.

Continuing Efforts to Improve Water Supply

Because of the difficulty in obtaining an adequate water supply, a decision was made to stretch 5-inch 

lines up the stairs to supply interior attack lines. The first line was stretched up the west (#1) stairwell 

to the 24th floor level and was operational by 0215, approximately six hours into the fire. At 0221, a 

12th alarm was sounded to stretch a second line, in the center (#2) stair. At 0455, a third 5-inch line 

was ordered stretched, in the east (#3) stair. The operation in the east stair was discontinued at the 

17th floor level at 0600. While the 5-inch lines were being stretched, a sprinkler contractor arrived 

at the scene and began manually adjusting the pressure reducing valves on the standpipe connections. 

This improved the discharge pressure in the hoses supplied by the standpipe system, finally providing normal handline streams for the interior fire suppression crews. At this point, however, the fire 

involved several floors and could not be contained with manual hose streams.

Firefighting Operations Suspended

All interior firefighting efforts were halted after almost 11 hours of uninterrupted fire in the building. Consultation with a structural engineer and structural damage observed by units operating in 

the building led to the belief that there was a possibility of a pancake structural collapse of the fire 

damaged floors. Bearing this risk in mind along with the loss of three personnel and the lack of 

5

The exact time that Engine 11 was assigned to attempt ventilation and the time the crew reported they were in trouble 

are not known, since the tactical radio channel they were using is not recorded and detailed time records of this event 

were not maintained during the incident. Estimates from individuals who were involved suggest that the assignment 

was made between 2130 and 2200 hours and search efforts were initiated between 2200 and 2230 hours. The bodies 

were located at approximately 0215 hours.
12 U.S. Fire Administration/Technical Report Series

progress against the fire despite having secured adequate water pressure and flow for interior fire 

streams, an order was given to evacuate the building at 0700 on February 24. At the time of the 

evacuation, the fire appeared to be under control on the 22nd though 24th floors. It continued to 

burn on floors 25 and 26 and was spreading upward. There was a heavy smoke condition throughout most of the upper floors. The evacuation was completed by 0730.

After evacuating the building, portable master streams directed at the fire building from several 

exposures, including the Girard Building #1 and One Centre Plaza, across the street to the west were 

the only firefighting efforts left in place.

Fire Stopped

The fire was stopped when it reached the 30th floor, which was protected by automatic sprinklers. 

As the fire ignited in different points this floor level through the floor assembly and by autoexposure 

through the windows, 10 sprinkler heads activated and the fires were extinguished at each point 

of penetration. The vertical spread of the fire was stopped solely by the action of the automatic 

sprinkler system, which was being supplied by fire department pumpers. The 30th floor was not 

heavily damaged by fire, and most contents were salvageable. The fire was declared under control at 

3:01 p.m., February 24, 1991.

ANAL

Smoke Movement

The heated products of combustion from a fire have a natural buoyancy, which causes them to accumulate in the upper levels of a structure. In a highrise building the stairways, elevator shafts, and 

utility shafts are natural paths for the upward migration of heated products of combustion.

Stack effect is a natural phenomenon affecting air movement in tall buildings. It is characterized by 

a draft from the lower levels to the upper levels, with the magnitude of the draft influenced by the 

height of the building, the degree of air-tightness of exterior walls of the building, and temperature 

differential between inside and outside air.6

 This effect was particularly strong on the night of the 

fire due to the cold outside temperature. Interior air leakage rates, through shaft walls and openings, 

also modulate the rate of air flow due to stack effect. Smoke and toxic gases become entrained in this 

normal air movement during a fire and are carried upward, entering shafts through loose building 

construction or pipe and duct penetrations. The air flow carries smoke and gases to the upper portions of the structure where the leakage is outward.

At the upper portions of the structure, smoke and toxic gases fill the floors from the top floor down 

toward the fire, creating a dangerous environment for building occupants and firefighters. During 

the investigation of this fire, this upward flow was evidenced by the presence of heavy soot in the 

38th floor mechanical room and all the upper floors of the building. The path of smoke travel to the 

upper floors was vividly evidenced by the soot remnants in HVAC shafts, utility chases, return air 

shafts, and exhaust ducts.

6 Fitzgerald, R. (1981), “Smoke Movement in Buildings,” in Fire Protection Handbook, 15th ed., McKinnon, G. P., ed., Quincy, 

MA: National Fire Protection Association, p. 3-32.
USFA-TR-049/February 1991 13

Fuel Loading

Fuel loading on the fire floors consisted mainly of files and papers associated with securities trading 

and management consulting. At least one floor had a significant load of computer and electronic 

equipment. In some cases, correlation could be found between heavy fuel load and damage to 

structural members in the affected area. From the 22nd floor to the 29th floor, the fire consumed all 

available combustible materials with the exception of a small area at the east end of the 24th floor.

Structural Conditions Observed

Prior to deciding to evacuate the building, firefighters noticed significant structural displacement 

occurring in the stair enclosures. A command officer indicated that cracks large enough to place a 

man’s fist through developed at one point. One of the granite exterior wall panels on the east stair 

enclosure was dislodged by the thermal expansion of the steel framing behind it. After the fire, there 

was evident significant structural damage to horizontal steel members and floor sections on most of 

the fire damaged floors. Beams and girders sagged and twisted--some as much as three feet--under 

severe fire exposures, and fissures developed in the reinforced concrete floor assemblies in many 

places. Despite this extraordinary exposure, the columns continued to support their loads without 

obvious damage.

InCIDenT COMManD

During nearly 19 hours of firefighting, the Philadelphia Fire Department committed approximately 

316 personnel operating 51 engine companies, 15 ladder companies, and 11 specialized units, 

including EMS units, to the 12-alarm incident. The incident was managed by 11 battalion chiefs 

and 15 additional chief officers under the overall command of the Fire Commissioner. All apparatus 

and personnel were supplied without requesting mutual aid. Off-duty personnel were recalled to 

staff reserve companies to maintain protection for all areas of the city. Philadelphia uses an incident 

management system known within the department as Philadelphia Incident Command (PlC). It is 

based on the ICS system taught at the National Fire Academy.

Operations

The Department’s standard operating procedures for a highrise incident were implemented at the 

time of arrival. Incident commanders were confronted with multiple simultaneous systems failures. 

As a result, command and control decisions were based on the need to innovate and to find alternate 

approaches to compensate for the normal systems that firefighters would have relied on to bring this 

incident to a more successful conclusion.

Philadelphia Fire Department tactical priorities in a highrise fire focus on locating and evacuating 

exposed occupants and making an aggressive interior attack to confine the fire to the area or at least 

the floor of origin. Confronted with total darkness, impaired vertical mobility because the elevators were inoperable, water supply deficiencies which made initial attack efforts ineffective, vertical 

fire spread via unprotected interior openings and external auto-exposure, and worsening heat and 

smoke conditions in the stairways, the tactical focus shifted to finding something (perhaps anything) 

which could be accomplished safely and effectively.

When Engine 11’s crew reported their predicament, the priority changed to attempting to locate 

and rescue the trapped firefighters. Unfortunately, these efforts were in vain and nearly proved tragic 
14 U.S. Fire Administration/Technical Report Series

when the eight firefighters conducting search and rescue operations became disoriented and ran out 

of air in the 38th floor mechanical room and nearly perished while trying to locate a roof exit. The 

rescue of these members was extremely fortunate in a situation that could have resulted in an even 

greater tragedy.

Communications

As is often the case, communication at such a large incident presented a serious challenge to maintaining effective command and control. The loss of electrical power plunged the entire building into 

total darkness, forcing firefighters to rely on portable lights. This impacted even face-to-face communications by making it difficult for people to identify with whom they were talking.

Radio communication was also affected by the significant duration of the incident. A field communications van was brought to the scene early in the incident with a supply of spare radios and 

batteries, but it was a major challenge to provide charged batteries for all of the radios that were in 

use in the incident.

To ease congestion on fireground radio channels, cellular telephones were used to communicate 

between the Command Post in the lobby and the staging area on the 20th floor. Several other communications functions took advantage of the cellular telephone capability.

Logistics

The Logistics Section was responsible for several functions including refilling SCBA cylinders, supplying charged radio batteries, and stretching the 5-inch supply line up the stairways. These were 

monumental endeavors which required the labor of approximately 100 firefighters. Equipment 

and supplies were in constant demand including handlights and portable lighting, deluge sets, 

hose, nozzles and other equipment. The Staging Area on the 20th floor included the Medical and 

Rehabilitation sectors.

The Philadelphia Fire Department used its highrise air supply system to refill air cylinders on the 

20th floor. Falling glass and debris severed the airline, which is extended from the air compressor 

vehicle outside the building to the staging area, and the system had to be repaired and reconnected 

at the scene.

Safety

When things go wrong on a scale as large as One Meridian Plaza, safety becomes an overriding 

concern. Firefighters were continually confronted with unusual danger caused by multiple system 

failures during this incident. The deaths of the three firefighters and the critical situation faced by 

the rescue team that was searching for them are clear evidence of the danger level and the difficulties 

of managing operations in a dark, smoke-filled highrise building.

A perimeter was set up around the building to prevent injuries from falling glass and stone panels, 

but it was necessary for personnel to cross this zone to enter and exit the building and to maintain 

the hoselines connected to the standpipe system. One firefighter was seriously injured when struck 

by falling debris while tending the hoselines. In addition, all supplies and equipment needed inside 

the building had to cross the safety perimeter at some point.
USFA-TR-049/February 1991 15

Many firefighters working inside the building were treated for minor injuries and fatigue during the 

fire. Rest and rehabilitation sectors contributed to firefighter safety by improving mental and physical stamina, and a medical triage treatment area was established on the 20th floor.

The physical and mental demands on personnel were extraordinary. In addition to managing the 

physical safety of personnel, their emotional and psychological well-being were considered. The 

department activated its critical incident stress debriefing program and relieved first and second 

alarm companies soon after discovering that the crew of Engine 11 had died on the 28th floor. 

More than 90 firefighters were debriefed on site after the dead firefighters were evacuated. The CISD 

involvement continued after the fire, due to the tremendous impact of the loss and the risk to the 

hundreds of firefighters who were involved in the incident.

The most courageous safety decision occurred when Fire Commissioner Roger Ulshafer ordered the 

cessation of interior firefighting efforts and evacuated the building due to the danger of structural 

collapse. Firefighters did not reenter the structure until the fire had been controlled by the automatic 

sprinklers on the 30th floor and burned out all of the available fuels on the fire-involved lower levels.

BUIlDInG anD FIRe ReGUlaTIOns

When One Meridian Plaza construction began in 1968, the City of Philadelphia was enforcing the 

1949 edition of the Philadelphia Building Code. This code was of local origin and contained minor 

amendments that had been incorporated since its enactment. This building code made no distinction between highrise and other buildings; and therefore, no special highrise construction features 

were required. The general focus of the code was to provide a high degree of fire-resistive construction rather than relying on automatic sprinkler protection or compartmentation.

In 1984, Philadelphia switched from a locally developed building code to one based on the BOCA 

Basic Building Code/1981. That code has since been updated, and the BOCA National Building Code/1990 

is currently in force in Philadelphia. Both of these codes contain provisions expressly addressing 

highrise building fire protection, including a requirement for automatic sprinkler systems in all new 

highrise buildings.

As a result of this fire, the City of Philadelphia has adopted an ordinance requiring all existing highrise buildings to be protected by automatic sprinklers by 1997. Also, officials of the Philadelphia 

Fire Department have discussed proposing adoption of the BOCA National Fire Prevention Code with local 

amendments, as opposed to continuing to develop their Philadelphia Fire Prevention Code locally.

In 1981, the City enacted amendments to its Fire Code requiring the installation of special fire protection features in existing highrise buildings. These modifications included:

•	 Fire	 alarm	 systems	 with	 smoke	 detection	in	 elevator	 lobbies,	 entrances	to	 exit	 stairways,	

return air plenums, corridors, and other common or public areas.

•	 Stairway	identification	signs,	(i.e.,	identification	of	the	stairway,	floor	level,	and	the	top	and	

bottom levels of the stairway).

•	 Stairway	re-entry	to	permit	occupants	to	retreat	from	stairways	compromised	by	smoke	or	

fire and return to tenant spaces. (In the event doors were locked from the stairway side for 

security reasons, provisions had to be made to unlock doors automatically upon activation of 

the fire alarm system.)
16 U.S. Fire Administration/Technical Report Series

In November 1984, the Philadelphia Department of Licenses and Inspections issued a notice of 

violation to the owners of One Meridian Plaza requiring compliance with these amendments. The 

Board of Safety and Fire Prevention later granted the owners a variance to permit stairway doors to 

be locked, provided that doors were unlocked to permit re-entry every third floor.7

FIRe CODe enFORCeMenT

The preparation and adoption of fire safety regulations is managed by the Philadelphia Fire Department 

under the direction of the fire marshal. However, the department does not perform or direct compliance inspections of individual properties. Fire code enforcement is delegated to the Department 

of Licenses and Inspections (L&I) by city charter. This department performs the functions of the 

building official in Philadelphia.

The fire department conducts inspections of properties applying for variances, follows-up citizen 

complaints, and makes referrals to L&I. The block inspection program detailed in Fire Department 

Operational Procedure 4 (see Appendix F) provides for the annual inspection of all buildings except 

one and two family dwellings. However, fire department activities to detect and abate hazards are 

primarily of an educational nature. Guidelines for referring serious or continuing hazards to L&I are 

not detailed in the Block Inspection procedure; however, information regarding the maintenance of 

referral and appeal records for individual properties is detailed.

It has been questioned whether the working relationship between line company personnel, the fire 

marshal’s office, and the Department of Licenses and Inspections produces effective fire code compliance. Senior fire department officials have expressed considerable dissatisfaction with the relationship between the fire department and L&I, and continue to advocate a more active role for the fire 

department in code enforcement matters.

Fire inspection records for One Meridian Plaza were examined after the fire to document code 

enforcement actions requiring the installation or upgrade of fire protection features required by the 

1981 fire code amendments. An August 17, 1990, L&I violation notice cited the owner for failing 

to pay a non-residential inspection fee and noted that a reinspection would be conducted within 30 

days. However, no record of a subsequent inspection was produced.

LESS

Perhaps the most striking lesson to be learned from the One Meridian Plaza highrise fire is what can 

happen when everything goes wrong. Major failures occurred in nearly all fire protection systems. 

Each of these failures helped produce a disaster. The responsibility for allowing these circumstances 

to transpire can be widely shared, even by those not directly associated with the events on and before 

February 23, 1991.

To prevent another disaster like One Meridian Plaza requires learning the lessons it can provide. 

The consequences of this incident are already being felt throughout the fire protection community. 

Major code changes have already been enacted in Philadelphia (see Appendix G) and new proposals 

7Records and reports provided by the Philadelphia Fire Department during this investigation do not indicate the dates 

of either the appeal or this variance. Firefighters did report having to force entry on several floors during firefighting 

because some stairway doors were locked.
USFA-TR-049/February 1991 17

are under consideration by the model code organizations. These changes may eventually reduce the 

likelihood of such a disaster in many communities.

1. Automatic sprinklers should be the standard level of protection in highrise buildings.

The property conservation and life safety record of sprinklers is exemplary, particularly in highrise buildings. While other fire protection features have demonstrated their effectiveness over 

time in limiting losses to life and property, automatic sprinklers have proven to provide superior 

protection and the highest reliability. Buildings in some of the nation’s largest cities, designed 

and built around effective compartmentation, have demonstrated varying success at containing 

fires, but their effectiveness is often comprised by inadequate design or installation and may not 

be effectively maintained for the life of the building. Even with effective compartmentation, a 

significant fire may endanger occupants and require a major commitment of fire suppression 

personnel and equipment. Retrofitting of automatic sprinklers in existing buildings has proven 

effective in taking the place of other systems that have been found to be inadequate.

2. Requirements for the installation of automatic sprinklers are justified by concerns about 

firefighter safety and public protection effectiveness, as well as traditional measures such as 

life safety and property conservation.

The property protection value of sprinklers was recognized long before life safety became a 

popular justification for installing fire protection. Life safety has become the primary concern in 

recent times, justifying the installation of automatic sprinklers in highrise buildings. The value 

of sprinklers as a means of protecting firefighters has rarely been discussed.

Members of the fire service should promote automatic fire sprinklers if for no other reason 

than to protect themselves. Requiring the installation and maintenance of built-in fire protection should become a life safety issue for firefighters.8

 The opposition to retrofit protection has 

consistently cited cost concerns. Communities need to be made aware that the costs they defer 

may be paid by firefighters in terms of their safety. This is above and beyond the potential loss 

to citizens and businesses that is usually considered.

3. Code assumptions about fire department standpipe tactics proved invalid.

One of the principal code assumptions affecting fire department operations at One Meridian 

Plaza concerned the installation of standpipe pressure reducing valves. The rationale for PRVs 

is the concern that firefighters would be exposed to dangerous operating pressures and forces 

if they connected hoselines to outlets near the base of standpipe risers of substantial height, 

particularly those supplied by stationary fire pumps. For example, in a 275 foot high standpipe zone (the 

highest permitted using standard pipe and fittings), a pressure of 184 psi is required at the base of the riser to overcome 

elevation and produce the minimum required outlet pressure of 65 psi at the top of the riser. At this pressure, a standard 

2-1/2-inch fire hose fitted with a 1-1/8-inch straight bore nozzle would produce a back pressure (reaction force) in 

excess of 500 pounds. This is a well-founded concern; however, it is built upon the assumption 

that fire departments use 2-1/2-inch attack lines and straight bore nozzles to attack fires from 

standpipes. Most fire departments today use 1-3/4-inch and 2-inch hose with fog nozzles 

8A study by Charles Jennings reports that the firefighter injury rate in non-sprinklered highrise buildings is seven 

times higher than in comparable buildings equipped with automatic sprinklers. “In Highrise Fires, Sprinklers Beat 

Compartmentation —Hands Down.” U.S. Fire Sprinkler Reporter, April 1992, pp. 1,5-7.
18 U.S. Fire Administration/Technical Report Series

for interior attack. These appliances require substantially greater working pressures to achieve 

effective hose streams.

In the aftermath of this incident, the NFPA Technical Committee on Standpipes has proposed a 

complete revision of NFPA 149 to more closely reflect current fire department operating practices. Section 5-7 of the proposed standard requires a minimum residual pressure of 150 psi 

at the required flow rate from the topmost 2-1/2-inch hose outlet and 65 psi at the topmost 

1-1/2-inch outlet (presumably for occupant use). Minimum flow rates of 500 gpm for the 

first standpipe and 250 gpm for each additional standpipe remain consistent with past editions 

of the standard. The proposed new requirements limit the installation of pressure regulating 

devices to situations where static pressures at hose outlets exceed 100 psi for occupant use hose 

or 175 psi for fire department use hose. This will provide substantially greater flow and pressure margins for fire department operations. These requirements are intended to apply to new 

installations and are not retroactive.

Firefighters at One Meridian Plaza had great difficulty determining how to improve flow and 

pressure from hose outlets during the fire. Even if firefighters could have closely examined 

the valves, with good light and under less stressful conditions, it is unlikely that they would 

have been able to readjust the valves. Numerical indicators on the valve stems represented 

an index for adjustment not the actual discharge pressure. (This may have confused the 

technicians responsible for installing and maintaining the valves. Investigators found valves 

set at “20” and “80” on the index markings. To achieve 65 psi would have required a setting 

from 88 to 91 on the index. A setting of 150 to 158 was necessary to produce the maximum 

allowable 100 psi.)

Pressure regulating devices come in three different types:

•	 Pressure restricting devices which reduce pressure under flowing conditions by reducing 

the cross- sectional area of the hose outlet.

•	 Pressure control valves are pilot-operated devices which use water pressure within the system to modulate the position of a spring-loaded diaphragm within the valve to reduce 

downstream pressure under flowing and non-flowing conditions.

•	 Pressure reducing valves use a spring-loaded valve assembly to modulate the position of 

the valve disc in the waterway to reduce the downstream pressure under flowing and 

non-flowing conditions.

Further differentiation within each of these types results from differences in manufacturer 

specifications. (Details are provided in the Philadelphia Fire Department fact sheet on pressure 

regulating devices in Appendix G.) Some devices are field adjustable, some are not. Some can 

be removed to permit full, unrestricted flow, others cannot. 

9

The report of the Technical Committee on Standpipes appears in the NFPA 1992 Fall Meeting Technical Committee Reports, 

pp 331-367.
USFA-TR-049/February 1991 19

4. The requirements and procedures for design, installation, inspection, testing, and maintenance of standpipes and pressure reducing valves must be examined carefully.

The proposed revision of NFPA 14 (1993) and a new NFPA document, NFPA 25, Standard for 

the Installation, Testing, and Maintenance of Water-Based Fire Protection Systems (1992), address many of the 

concerns arising from this fire regarding installation and adjustment of pressure reducing valves. 

NFPA 14 requires acceptance tests to verify proper installation and adjustment of these devices. 

NFPA 25 requires flow tests at five year intervals to verify proper installation and adjustment.

Neither of these standards proposes changes in the performance standards for the design of 

pressure reducing valves.

Standard performance criteria for the design and operation of each type of valve should be 

adopted to encourage user-friendly designs that will permit firefighters to achieve higher pressure and flow rates without interrupting firefighting operations. The operation and adjustment 

of valves should be easy to identify and clearly understandable by inspection and maintenance 

personnel without reliance on detailed operating or maintenance instructions.

It is extremely important to have all systems and devices thoroughly inspected and tested at the 

time of installation and retested on a regular basis. Fire suppression companies that respond to 

a building should be familiar with equipment that is installed in its fire protection systems and 

confident that it will perform properly when needed.

5. Inconsistencies between code assumptions and firefighting tactics must be addressed.

The inconsistency between fire department tactics and design criteria for standpipe hose outlet 

pressures was widely recognized before this fire. However, little was done to change fire department tactics or to amend the code requirements for standpipe installations.

Fire departments utilize lightweight hose and automatic nozzles for the same reasons the code 

requires pressure reducing valves: firefighter safety. The inconsistency between these approaches 

can cause serious problems. Where pressure reducing valves are not installed, fire departments 

can usually augment water supplies by connecting to the fire department connections. However, 

when contemporary firefighting tactics are employed and improperly adjusted PRVs are installed, 

the combination is likely to produce hose streams with little reach or effectiveness.

The PRV equipped hose outlets on the 22nd floor of One Meridian Plaza, adjusted as reported 

at the time of the fire, would have produced nozzle pressures of approximately 40 psi. This is 

insufficient for a straight stream device and dangerously inadequate for a fog nozzle.

Standard operating procedures for highrise buildings, particularly those not protected by automatic sprinklers, should reflect the potential need to employ heavy firefighting streams, which 

may require higher flows and pressures.

6. Pre-fire planning is an essential fire department function.

The availability of information about the building was a problem in this incident.

The purpose of conducting pre-fire plans is to gather information about buildings and occupancies from the perspective that a fire will eventually occur in the occupancy. This information 

should be used to evaluate fire department readiness and resource capabilities. At a fire scene, 

pre-fire plan information can be used to formulate strategies for dealing with the circumstances 

which present themselves.
20 U.S. Fire Administration/Technical Report Series

Pre-fire planning activities should identify building and fire protection features which are likely 

to help or hinder firefighting operations and record this information in a format usable to firefighters at the scene of an emergency. Recognizing and recording information about restricting 

devices and pressure reducing valves should be among the highest priorities. Information on 

fire alarm systems and auxiliary features such as elevator recall, fan control or shutdown, and 

door releases should also be noted.

The fire department was unable to obtain important details about the installed fire protection 

at One Meridian Plaza during critical stages of the fire attack. Detailed information about the 

design and installation of standpipes, pressure relief valves and the fire pump, could have aided 

firefighters significantly if it had been available earlier in the fire.

Pre-fire plans and standard operating procedures should also consider evacuation procedures 

and plans for the removal of occupants.

7. Standard Operating Procedures (SOPs) and training programs for fires in highrise buildings should reflect the installed protection and highrise fire behavior.

Training and SOPs should consider ways to achieve adequate fire flow with available pressures 

and ways to improve flow and pressure when required. Tactics for placing multiple lines in 

service simultaneously must also be developed and discussed.

Extensive pre-fire planning and training are required for fire department control of mechanical smoke management systems to be effective. Training in the management of smoke should 

consider stack effect and the ability to predict and/or direct ventilation in a real incident.

8. Safety-oriented strategies should dominate command decisions when multiple systems 

failures become evident.

This incident presented command officers with an unprecedented sequence of system failures. 

As more things went wrong, officers had to seek alternative approaches to manage the situation. 

The time pressure and stress of fireground command can make it difficult to thoroughly evaluate 

each alternative approach, particularly as new and unanticipated problems are presented in rapid 

succession. Conservative tactics, oriented toward protecting the firefighters who must execute 

them, should take precedence when confronted with an unknown and unanticipated situation, 

since the potential consequences of fireground decisions can rarely be fully evaluated during 

the incident. As much as possible, these alternatives should be considered beforehand in prefire planning, standard operating procedures, and training materials, and by reviewing post-fire 

critiques and reports of other incidents. This is an incident that will make a major contribution 

to the knowledge of what can and will happen when major system failures occur in the worst 

imaginable sequence.

9. Fire code enforcement programs require the active participation of the fire department.

In Philadelphia, responsibility for the fire code is fragmented. The fire department is responsible for developing and maintaining fire code requirements, supervising the appeals process, and 

investigating and referring fire code complaints. However, it does not conduct regular periodic 

code enforcement inspections, issue permits, or develop target hazard protocols for ensuring that 

inspections conducted by the responsible agency are addressing critical fire protection problems.
USFA-TR-049/February 1991 21

Many of the model code requirements that apply to highrise buildings are predicated upon 

assumptions about firefighting strategies and tactics. Most model code organizations designate 

the fire department, fire prevention bureau, or fire marshal’s office as the principal enforcement 

authority for fire protection system requirements. Fire department personnel are in the best 

position to validate code assumptions and see that the built-in fire protection and life safety 

systems are functional and compatible. Moreover, the first-hand knowledge and experience of 

firefighters with fire behavior is often an invaluable resource when interpreting fire and building 

code requirements.

10. Code provisions should be adopted requiring highrise building owners to retain trained 

personnel to manage fire protection and life safety code compliance and assist fire department personnel during emergencies.

Model fire prevention codes require building owners to develop highrise fire safety and evacuation plans to manage the life safety complexities of these buildings. The requirements are not 

specific about what must be included in these plans, and they give no explicit consideration to 

the problems of firefighting and property conservation.

Mandating the appointment and certification of individuals with specialized knowledge in code 

requirements and building systems would go a long way toward ensuring that the unique 

aspects of each highrise building are incorporated into detailed plans.

(New York City Local Law 5 requires that each owner designate a fire safety director. The responsibilities of this individual for managing the life safety plan during an incident are clearly established in this ordinance.)

11. Occupants and central station operators must always treat automatic fire alarms as though 

they were actual fires, especially in highrise buildings.

Building personnel, alarm services, and fire departments must develop an expectation that an 

automatic alarm may be an indication of an actual fire in progress. Automatic detection systems 

have gained a reputation for unnecessary alarms in many installations. This has caused an attitude of complacency that can be fatal in responding to such alarms. To change such attitudes and 

expectations, it will be necessary to improve the reliability and performance of many systems.

By choosing to investigate and verify the alarm condition, the building engineer nearly lost his life. If not for the ability 

to communicate with the lobby guard to relay instructions for manually recalling the elevator, this individual would likely 

have shared the fate of his counterpart who died in a service elevator at the First Interstate Bank Building Fire in Los 

Angeles (May 4, 1988).

Technological advances and improved maintenance procedures are the answers to solving the 

nuisance alarm problem. In addition to requiring regular maintenance of systems by qualified 

individuals, Philadelphia and other cities have stiffened the penalties on owners, occupants, and 

central station operators who fail to report automatic fire alarm activations.

12. Incomplete fire detection can create a false sense of security.

Automatic fire detectors, like automatic sprinklers, are components of engineered fire protection 

systems. A little protection is not always better than none. Over-reliance on incomplete protection may lead to a false sense of security on the part of building owners and firefighters alike.
22 U.S. Fire Administration/Technical Report Series

Automatic fire detectors can only notify building occupants or supervisory personnel at a central, remote, or proprietary station that an event has occurred, and in some cases initiate action 

by other systems to limit the spread of fire, smoke, or both. (In this case, automatic detectors 

initiated an alarm, recalled elevators, and shutdown air handling equipment; however an elevator was subsequently used to go to the fire floor to investigate the alarm.)

Smoke detectors at One Meridian Plaza were installed in particular areas as required by the 1981 

amendments to the fire code; that is at the point of access to exits, at the intakes to return air 

shafts, and in elevator lobbies and corridors. The apparent underlying logic was to protect the 

means of egress and to detect smoke in the areas where it was most likely to travel. It appears in 

this case that the partitions and suspended ceiling contained the smoke and heat during the fire’s 

incipient phase and prevented early detection. In all likelihood, the first detector may not have 

activated until after the room of origin had flashed-over. Shortly after flashover, the suspended 

ceiling in this area probably failed permitting the fire to spread throughout the return air plenum. Once the fire broke the exterior windows and established an exterior air supply there 

was little that could be done to control the fire. Firefighters were disadvantaged by the delay in 

reporting the fire.

13. Nationally recognized elevator code requirements for manual control of elevators during 

fire emergencies work.

Elevator control modifications at One Meridian Plaza were accomplished in accordance with 

Commonwealth of Pennsylvania requirements based on ANSI/ASME A17.l, Safety Code for Elevators 

and Escalators. The elevators performed as expected by the standard. The only problem with the 

elevator response was the decision of the building engineer to override the system to investigate 

the alarm.

14. The ignition source provided by oil-soaked rags is a long recognized hazard that continues 

to be a problem.

Had the contractor refinishing paneling on the 22nd floor not carelessly left oil soaked cleaning 

rags unattended and unprotected in a vacant office, this fire would not have occurred. To pinpoint the particular source of ignition of this fire as the sole cause of the death and destruction 

that followed is a gross oversimplification. Nevertheless, failure to control this known hazard 

is the proximate cause of this disaster. The danger of spontaneous heating of linseed oil-soaked 

rag waste is widely recognized. Each model fire prevention code requires precautions to prevent ignition of such materials. At a minimum, waste awaiting removal from the building and 

proper disposal must be stored in metal containers with tight-fitting, self-closing lids. Leaving 

these materials unattended in a vacant office over a weekend was an invitation to disaster. This 

is both an education and an enforcement problem for fire prevention officials.

15. Building security personnel should be vigilant for fire safety as well as security threats, 

especially while construction demolition, alteration, or repair activities are underway.

Earlier in the day, the building engineer had become aware of an unusual odor on the 22nd 

floor which he associated with the refinishing operations which were underway there. When 

the alarm system activated later that evening he first believed the solvent vapors had activated a 

smoke detector.
USFA-TR-049/February 1991 23

The roving security guard made no mention of anything unusual during his rounds of the fire 

area earlier in the evening. It is conceivable that no detectable odor of smoke or audible or visible 

signals of a fire were present when the guard last checked the floor. However, a cursory check 

is not adequate when construction, demolition, renovations, or repair activities are underway 

in a building area. Fire hazards are often associated with construction activities, and buildings 

are especially vulnerable to fire during such operations. For these reasons, it should be standard 

practice to check these areas even more carefully and thoroughly than usual. All building operating and security personnel should have basic training in fire prevention and procedures to be 

followed when a fire occurs.

16. Emergency electrical systems must be truly independent or redundant.

Article 700 of the National Electrical Code recognizes separate feeders as a means of supplying 

emergency power. However, Section 700-12(d) requires these services to be “widely separated 

electrically and physically...to prevent the possibility of simultaneous interruption of supply.” 

Installing the primary and secondary electrical risers in a common enclosure led to their almost 

simultaneous failure when the fire penetrated voids in the walls above the ceiling of the 22nd 

floor electrical closet. The intense heat melted conductor insulation resulting in dead shorts to 

ground which opened the overcurrent protection on each service interrupting power throughout the building.

Auxiliary emergency power capability was provided by a natural gas powered generator located 

in the basement mechanical room. This generator was intended to supply one elevator car in 

each bank, fire pumps, emergency lighting and signs, and the fire alarm system. However, this 

generator set failed to produce power when needed. (Generator maintenance records indicated 

a history of problems; however, the root cause or mechanism responsible for these problems 

was not identified.)

Supplying the generator from the building natural gas service also left the emergency power system vulnerable in the event of simultaneous failure of the electrical and gas public utilities. The 

transformers that provided power for the adjacent building were installed in the basement of the 

One Meridian Plaza Building. These transformers had to be shut down due to the accumulation 

of water in the basement, resulting in the loss of power to this building as well. As a result the 

elevators in the adjoining building could not be used.

17. The regulations governing fire-resistance ratings for highrise structural components should 

be re-evaluated.

The degree of structural damage produced during the fire at One Meridian Plaza suggests that 

the requirements for structural fire resistance should be reexamined. Floor assemblies deflected 

as much as three feet in some places. The fire burning on multiple floors may have produced 

simultaneous exposure of both sides of these assemblies, which consisted of concrete slabs on 

corrugated decks, supported by structural steel beam and girder construction, sprayed with 

cementitious fireproofing materials. The standard fire test for floor and ceiling assemblies 

involves exposure from a single side only.

Columns and certain other structural elements are normally exposed to fire from all sides. In 

this fire, the steel columns retained their structural integrity and held their loads. Experience in 
24 U.S. Fire Administration/Technical Report Series

this and similar highrise fires suggest that columns are the least vulnerable structural members, 

due to their mass and relatively short height between restraints (floor to floor). Major damage 

has occurred to horizontal members, without compromising the vertical supports.

The development of uniform criteria for evaluating structural fire endurance accompanied the 

development of skyscrapers in the early 20th century. Test methods developed at the beginning 

of the century became the first fire-resistance standard in 1909,10 which endures today as ASTM 

E119, Method of Fire Test of Building Construction and Materials. One of the principal criticisms of this 

standard has been its lack of correlation with actual fire conditions.

Many fire protection professionals believe that the standard time- temperature curve used to 

produce the standard fire exposure during testing is less severe than actual fires involving contemporary fuel loads. (The original test method was based on less volatile, primarily cellulosic, 

fuels, while modern plastics and hydrocarbon-based furnishings and finishes produce much 

more dangerous and severe fire exposures.) Others believe that the current test method works 

well because it provides a good yardstick for comparing the performance of different systems and 

has been in widespread use for many decades, generating volumes of data on many systems.11

18. Inspections must be conducted during and after construction to verify that penetrations in 

fire-resistance rated assemblies are properly protected.

Voids and so-called poke-throughs in horizontal and vertical fire separation assemblies presented 

ideal avenues of fire spread during the One Meridian Plaza fire. Openings in the partitions enclosing electrical equipment on the floor of origin permitted the fire to reach and damage the electrical 

risers, plunging firefighters into darkness early in the fire. Voids in stairwell enclosures permitted 

smoke to spread in stairwells making firefighting operations difficult and exposing upper floors. 

Smoke and fire also extended via pipe chases, and telephone and electrical closets.

Through-penetration protection has been a continuing concern and has received considerable 

attention in building and fire codes in recent years. Each of the model building codes now contains 

provisions requiring protection of poke-throughs in fire-resistance rated assemblies. Moreover, a 

whole new industry has been developed to fill the technological void in through-penetration 

protection which developed with the widespread acceptance of plastic pipe and cable.

The absence of fire dampers in mechanical system supply and return ducts at shaft penetrations 

on each floor is of particular concern. There is evidence of smoke and fire spread through the 

air handling system. Nationally recognized model building, fire, and mechanical codes have 

contained requirements for fire dampers in these locations for many years. The installation of 

smoke detectors in these locations was an ineffective substitute for protecting the integrity of 

smoke and fire barriers. This fire clearly illustrates that smoke and fire spread through mechanical system plenums, ducts, and shafts is substantial even without the aid of operating fans.12

10 Fitzgerald, R. W. (1981), “Structural Integrity During Fire,” in Fire Protection Handbook, 15th ed., McKinnon, G. P., ed., 

Quincy, MA: National Fire Protection Association, p. 5-62.

11 Actual conditions in most fires produce heat release curves similar to the standard exposure up to the point where oxygen, 

i.e., ventilation, becomes restricted by fire product release, i.e., smoke and heated gases. However, at this point, actual fires 

usually diminish in size unless ventilation improves or a renewed oxygen supply is established. Once refreshed with a new 

air supply, most fires will resume growth, reach a peak, and then diminish as the fuel supply is consumed.

12 HVAC fans were shut down at night and on weekends, and were not operating at the time of the fire.
USFA-TR-049/February 1991 25

19. Features to limit exterior vertical fire spread must be incorporated in the design of highrise 

buildings.

Exterior vertical fire spread or autoexposure can be a significant fire protection problem in construction of highrise buildings if interior fire growth is unrestricted. Because of the difficulty 

with retrofitting exterior features to restrict fire spread, the installation of automatic sprinklers 

to restrict fire growth is the most simple approach to managing this risk in existing buildings. 

Exterior features to prevent fire spread must usually be designed and built into new buildings. Many modern (international style) and post-modern building designs present difficult 

exterior fire spread challenges because of their smooth exterior facades and large glazing areas. 

Variegated exterior facades and larger noncombustible spandrels significantly reduce exterior 

fire spread effects by increasing the distance radiant and conductive heat must travel to stress 

exterior windows and to heat materials inside the windows on floors above the fire.

COnClUsIOn

The ultimate message delivered by this fire is the proof that automatic sprinklers are the most effective and reliable means at our disposal to protect highrise buildings. When all other systems failed, 

automatic sprinklers were successful in controlling the fire. The Philadelphia Fire Department was 

confronted with an essentially impossible situation and did a commendable job of managing the 

incident. The loss of three firefighters is a tragedy that will always be remembered by the Philadelphia 

Fire Department. Analysis of the situation reveals, however, that the toll could have been much 

worse, had it not been for the courage, skills, and experience of this department. Several extremely 

difficult decisions were made under the most severe conditions. This fire will also be remembered 

for the lessons that it brings with respect to fire protection systems. To work effectively, such systems 

must be properly designed, installed, and maintained. When those requirements are not satisfied, 

the results can be devastating, as clearly demonstrated by this incident.

S

In addition to references to codes and standards cited in the text, news media accounts of the fire, 

and interviews with officials of the Philadelphia Fire Department, the following resources were used 

in the preparation of this report:

Alert Bulletin: Pressure Regulating Devices in Standpipe Systems (May 1991). Quincy, MA: National 

Fire Protection Association.

Butters, T., and T. Elliott (March 1991). “How the Philadelphia FD Handled the Worst Highrise Fire 

in the City’s History,” IAFC On Scene, March 15, 1991.

Eisner, H., and B. Manning (August 1991). “One Meridian Plaza Fire,” Fire Engineering, August 1991. 

pp. 50-70.

Factory Mutual Engineering Corporation (March 1990). Highrise Buildings, Loss Prevention Data 

Sheet 1-3. Boston, MA: Factory Mutual Engineering Corporation.

Factory Mutual Engineering Corporation (December 1986). Pressure Reducing Valves for Fire 

Protection Service, Loss Prevention Data Sheet 3-11. Boston, MA: Factory Mutual Engineering 

Corporation.
26 U.S. Fire Administration/Technical Report Series

Klem, T. J. (May 1991). Preliminary Investigative Report: One Meridian Plaza, Philadelphia, PA, 

February 23, 1991, Three Fire Fighter Fatalities. Quincy, MA: National Fire Protection Association.

Klem, T. J. (September/October 1991). “Highrise Fire Claims Three Philadelphia Fire Fighters,” 

NFPA Journal, Sept/Oct 1991. pp. 64- 67, 89.

Linville, J. L., ed. (1991). Fire Protection Handbook, 17th ed. Quincy, MA: National Fire Protection 

Association.

McKinnon, G. P., ed. (1981). Fire Protection Handbook, 15th ed. Quincy, MA: National Fire Protection 

Association.

One Meridian Plaza: 12-Alarm Highrise Fire (1991), Philadelphia, PA: Philadelphia Fire Films. 

Videotape.
27

App

NORTH ELEVATION 

1414 South Penn Square 

One Meridian Plaza 
28 U.S. Fire Administration/Technical Report Series

A

One Meridian Plaza 

22nd Floor 

772-11-10-92-1

R11-23-92
29

Appendix B

Building Emergency Instructions
30

Appendix C

Philadelphia Fire Department 

Highrise Emergency Procedures
USFA-TR-049/February 1991 31

Appendix C (continued)
32 U.S. Fire Administration/Technical Report Series

Appendix C (continued)
USFA-TR-049/February 1991 33

Appendix C (continued)
34 U.S. Fire Administration/Technical Report Series

Appendix C (continued)
USFA-TR-049/February 1991 35

Appendix C (continued)
36

Appendix d

Factory Mutual Engineering Corporation 

Pressure Reducing Valve Loss Prevention Data Sheet
USFA-TR-049/February 1991 37

Appendix d (continued)
38 U.S. Fire Administration/Technical Report Series

Appendix d (continued)
39

Appendix e

Philadelphia Fire Department 

Pressure Regulating Device Fact Sheet
40 U.S. Fire Administration/Technical Report Series

Appendix e (continued)
USFA-TR-049/February 1991 41

Appendix e (continued)
42 U.S. Fire Administration/Technical Report Series

Appendix e (continued)
USFA-TR-049/February 1991 43

Appendix e (continued)
44 U.S. Fire Administration/Technical Report Series

Appendix e (continued)
USFA-TR-049/February 1991 45

Appendix e (continued)
46 U.S. Fire Administration/Technical Report Series

Appendix e (continued)
47

Appendix F

Philadelphia Fire Department Block Inspection Program
48 U.S. Fire Administration/Technical Report Series

Appendix F (continued)
USFA-TR-049/February 1991 49

Appendix F (continued)
50 U.S. Fire Administration/Technical Report Series

Appendix F (continued)
USFA-TR-049/February 1991 51

Appendix F (continued)

E.

1.
52 U.S. Fire Administration/Technical Report Series

Appendix F (continued)

6.
USFA-TR-049/February 1991 53

Appendix F (continued)
54 U.S. Fire Administration/Technical Report Series

Appendix F (continued)
55

Appendix G

Philadelphia Fire Code Amendments Adopted after the 

One Meridian Plaza Fire
56 U.S. Fire Administration/Technical Report Series

Appendix G (continued)
USFA-TR-049/February 1991 57

Appendix G (continued)
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Appendix G (continued)
USFA-TR-049/February 1991 59

Appendix G (continued)
60 U.S. Fire Administration/Technical Report Series

Appendix G (continued)
USFA-TR-049/February 1991 61

Appendix G (continued)
62

App

Numerous slides and photographs are included with the master report at the United States Fire 

Administration. The photographs presented on the following pages were taken by Charles Jennings 

after the fire, except where otherwise noted.
USFA-TR-049/February 1991 63

Philadelphia Inquirer photo by Michael S. Wirtz

Exterior view of One Meridian Plaza and fireground operations in the early 

morning hours of February 24, 1991. Fire involves the 22nd, 23rd, 24th, 

and part of the 25th floors. Note the heavy stream played on the 

exterior from an adjacent building.

A
64 U.S. Fire Administration/Technical Report Series

Philadelphia Inquirer photo by Michael Mally

Aerial view of exterior firefighting operations after dawn on February 24, 1991.

A
USFA-TR-049/February 1991 65 Philadelphia Inquirer photo by Michael Mally Exterior firefighting efforts from the Girard Building #1, east of One Meridian Plaza. The two buildings are connected on lower floors.

A
66 U.S. Fire Administration/Technical Report Series

A

Philadelphia Inquirer photo by Rick Bowmer

Smoke pours from One Meridian Plaza as William Penn looks on from atop Philadelphia City Hall the 

morning of February 24, 1991, after interior firefighting efforts have been suspended.
USFA-TR-049/February 1991 67

A

Philadelphia Inquirer photo by Michael Mally

View of deluge set operating from One Centre Square.
68 U.S. Fire Administration/Technical Report Series

A

Exterior view of building looking south from City Hall Plaza.
USFA-TR-049/February 1991 69

A

Exterior view of south side of building.
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A

This stairway connected the One Meridian Plaza Building with the adjacent office building.
USFA-TR-049/February 1991 71

A

Here and in the next two photos exterior granite panels from the east stair tower were dislodged due to the thermal 

expansion of the steel frame of the building.
72 U.S. Fire Administration/Technical Report Series

A
USFA-TR-049/February 1991 73

A
74 U.S. Fire Administration/Technical Report Series

A

Photo by James David

One of the areas of fire penetration on the 30th floor where a single sprinkler head activated to stop the upward extension 

of the fire.
USFA-TR-049/February 1991 75

A

Close-up of crack in concrete floor, 28th floor.
76 U.S. Fire Administration/Technical Report Series

A

Here and in the next three photos are interior views of floor areas after the fire. Note the total consumption of the available 

fuel and sagging of the floor deck of up to three feet between columns.
USFA-TR-049/February 1991 77

A
78 U.S. Fire Administration/Technical Report Series

A
USFA-TR-049/February 1991 79

A
80 U.S. Fire Administration/Technical Report Series

A

Detail of typical Type 1B construction, 6th floor. Note the spray-applied fireproofing and framing for gypsum wallboard.
USFA-TR-049/February 1991 81

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Fire tower between 25th and 26th floors. Note heavy fire and smoke damage.
82 U.S. Fire Administration/Technical Report Series

Appendix H (continued)

Occupant use standpipe hose cabinet on 26th floor.
USFA-TR-049/February 1991 83

A

Standpipe hose outlet with pressure reducing valve (PRV), 26th floor.
84 U.S. Fire Administration/Technical Report Series

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Photo by James David

Electrical shaft enclosure on the 30th floor, showing side-by-side risers for 

the two power supplies, both damaged by fire penetration at the plenum 

level of the adjoining office space.
USFA-TR-049/February 1991 85

A

Section of 5-inch hose that was ruptured by falling debris outside the building. Hose lines feeding the standpipes and 

entering the stairways were damaged several times and had to be replaced at great risk to firefighters. (Shoring boards were 

later used to protect the hose lines.)
86 U.S. Fire Administration/Technical Report Series

A

Street in front of the building from front steps showing stranded autos and debris in street.
USFA-TR-049/February 1991 87

A

Rooftop heliport.