Investigation of the Cook County Administration Building Fire Daniel Madrzykowski, P.E., FSFPE William D. Walton, P.E., FSFPE Building and Fire Research Laboratory National Institute of Standards and Technology Gaithersburg, MD

Cook County Administration Building Fire October 17, 2003  Fire in a storage room, 12 th floor  Approx. 5 PM, Friday  Security calls for complete evacuation  FD can not make successful interior attack  Tower ladders used to make fire attack  6 people die in the SE Stairway, 13 more rescued at approx 6:30 PM

View of north side of the Cook County Administration Building: 2 “half windows” were broken out. View of east side of the Cook County Administration Building

Investigations/Reviews Chicago Fire Department  Office of Fire Investigation  Operations Chicago Police Department  Bomb and Arson Cook County  Mikva Commission %20County%20Report%20Final.pdf

Investigations/Reviews -continued State of Illinois  James Lee Witt and Associates - Full Report  NIST – Fire Study  National Research Council Canada – Human Behavior Study

Building Construction  37 stories tall with one level below grade  Reinforced cast-in-place concrete with concrete and glass panel exterior walls  Core contains elevators and two stairs  Southeast stairs were designed as a “smoke-proof tower”  Partition walls were 1.59 cm (5/8 in) thick type X gypsum board on steel studs. Partitions extended from floor to a drop ceiling in all areas except the core.  Space above ceiling is return air plenum

12 th Floor

Area of Significant Fire Damage

NIST Investigation  No origin and cause – Used witness testimony to determine initial fire location  Document Scene  Fuel, ventilation, damage  Heat Release Rate Experiments  FDS Modeling  Examine different vent conditions in the SE stair  Examine potential impact of sprinklers

Doorways to Suite 1240 North Corridor South Corridor

Open Plan Office Area

NE Office

Exemplars – Suite 1210

Cone Calorimeter –ASTM 1354 Measures  Heat Release Rate (HRR)  Mass Loss Rate  Smoke production  Combustion gases

Cone Calorimeter

Materials Tested

ItemExposure Heat Flux 35 kW/m 2 70 kW/m 2 Avg. Peak HRR (kW/m 2 ) Avg. Peak HRR (kW/m 2 ) Carpeting Ceiling Tile1040 Monitor Case Letter Tray Chair Paper w/cb Wastebskt Wk Stn WS Cone Calorimeter Results

Sled Based Chair

Sled Base Chair HRR

Office Chair

Office Chair HRR

Single Work Station

Work Station HRR

Four Work Stations

Four Workstation video

Multiple Work Station HRR

Fire Models Zone Models - Divide room into two zones

Fire Models Field Models - Computational Fluid Dynamics Divide room into large number of small boxes or volumes

Computer based fire model Computational fluid dynamics model based on conservation of : –Mass –Energy –Momentum Predicts gas temperature, gas velocity Accounts for convective and radiation heat transfer Tracks combustion chemistry NIST Fire Dynamics Simulator (FDS)

Scientific visualization tool –Forms color graphics based on FDS calculated values. Smokeview

Building overview video

FDS Input  Only the 12 th floor simulated  Southeast stairs 12 th to 27 th floors  A small flaming fire with a prescribed burning rate was used to initiate the fire in the storage room based on witness testimony  Burning paper assumed to fall from piles outside storage room

FDS Input  Drop ceiling and exterior windows removed during simulation (times based on investigation)  Simulation terminated at 990 s (16 min 30 s) when fire department is believed to have applied water.

Flames and Smoke Video

Impact of Smoke Shaft in Southeast Stairs  Door from corridor to vestibule and door from vestibule to stairway opened at 930 s (15 min 30 s) into the simulation. (fire department advances hose line to floor)  Simulations with and without functioning vent

Stair video

Southeast Stair Temperatures Vent closedVent open

Southeast Stair Velocities Vent closedVent open

Sprinklers Used in Simulation  Typical standard response, K-5, pendent sprinklers  K factor of 81 L/min/(bar) ½  Activation temperature of 74° C (165° F)  Response time index of 150 (m·s) ½  Each sprinkler was centered in one half of the storage room

Sprinkler video

Summary  Documented HRRs from “typical” office furnishings  Simulated fire spread for first 16 min 30 s  Smoke in stairs comparable with or without smoke vent operation  Automatic fire sprinklers would have limited fire to room of origin

More information: Reference: NIST SP-1021, Cook County Administration Building Fire, 69 W. Washington, Chicago, IL, October 17, 2003, Heat Release Rate Experiments and FDS Simulations, July fire.nist.gov