The National Institute of Technology today released its findings on the June 2007 Sofa Super Store Fire in Charleston, S.C. A flashover and structural collapse contributed to the deaths of nine trapped Charleston firefighters on June 18, 2007. The study found that the unique layout of furniture store, its fuel content and lack of automatic sprinklers led to the rapid spread of the fire. Volume I and Volume II of the report discussed the event in detail and are now available for a 30-day public comment period, said Nelson Bryner, deputy division chief for Fire Research Division of NIST’s Engineering Laboratory.

Bryner said NIST conducted the study to determine why and how the fire spread so quickly; to measure the conditions within the structure in terms of temperature, oxygen concentration and smoke movement; and to identify specific areas in fire codes that warrant revision. He emphasized it focused on fire science, not the tactics used by fire command before, during and after the fire.

“It did not study how the nine firefighters lost their lives by becoming trapped and whether decisions made during and after were right decisions,” he said.

The task was to study how a fire that started at the loading dock spread throughout the 15,000-square-foot warehouse. Bryner said with computer modeling software, researchers inputted data about the fire and used basic physics of fire spread to simulate variables. One of the main issues the fire department faced was an invisible fire. He explained that during the incident, flames burned in the void space above the showroom in a drop ceiling for about 5 minutes and was not visible.

“Recall that the assistant chief had arrived, walked from the front of the main showroom to the rear at least two times and did not see any fire or smoke at all,” he said. “In a subsequent trip, he opened the door at the loading dock and it was jerked out of his hand.”

Bryner said the fire at that point was searching for air and pulling it from the west showroom and other areas. Later, it moved into the rear showroom and — given the amount of fuel — should have quickly progressed to the front of the store. However, it remained in the back of the store because it was ventilation limited. It wasn’t until firefighters broke out the front windows of the warehouse that enough oxygen was available to fuel the fire and move it rapidly to the front, he said.

“Once it came out of the front on the west side of the show room, it moved over to the east side and basically sealed the front of the store, or the main showroom,” Bryner said. “That’s what likely trapped the firefighters who were in the main showroom.”

Researchers found that lack of sprinklers, non-fire roll-up dock doors and the wood framing of the loading dock contributed to the dangerous conditions. He said their study found sprinklers inside a loading dock would have controlled fire in less than 1.5 minutes. In addition, there were no sprinklers in the showrooms or warehouse.

As a result, NIST recommend that state and local jurisdictions adopt model building and fire codes covering new and existing high-fuel-load mercantile occupancies, in addition to implementing aggressive fire inspection and enforcement programs. Bryner said authorities also should adopt and enforce model code requirements for sprinkler systems for all new commercial retail furniture stores regardless of size and for existing retail furniture stores with any single display area of greater than 190 m² (2,000 ft²).

Bryner further commented that furniture warehouses provide a unique risk because of the high quantities of foam-filled furniture and large, open spaces. Researchers estimated that the energy content of furniture in the store’s main showroom equaled about 4,000 gallons of gasoline.

“The fuel load and open space provides for a unique fire hazard,” he said. “That’s why we recommended the display areas must be sprinklered or they need to be broken up into smaller areas, or about 2,000 square feet. If that main showroom had been broken up … you would have been fighting fires in smaller areas and the fire growth wouldn’t have been so quick.”

Fire can grow and spread in concealed fashions for a considerable amount of time, Bryner added. At inopportune moments, it can make itself visible.

“As chiefs looks at structures like these that are not sprinklered, the ones with high fuel load, you need to be thinking whether the fire is growing in a concealed way and I can’t see it,” he said.

Sidebar: NIST's Study Recommendations
Timeline: Sofa Super Store Fire