Opening Statement—News Media Briefing Technical Study of the Sofa Super Store Fire
For Immediate Release: October 28, 2010
Michael E. Newman
Nelson Bryner, Study Team Leader and Deputy Division Chief, Fire Research Division National Institute of Standards and Technology
Thank you, Bill. Good afternoon. As Bill has just mentioned, NIST is a scientific research agency. We chose to study the Charleston Sofa Super Store fire because it was clearly an unusual and tragic event. We hoped to learn new information that would be helpful to firefighters and the public in the future.
Today I'd like to summarize what we found about:
Our study was focused on our specific expertise, fire science, and we cannot tell you based on our findings how or why the firefighters became trapped. We also cannot tell you whether the decisions made before, during, or after the fire were right or wrong. What we can tell you with reasonable accuracy is the probable technical cause of the fire's rapid spread and what actions can be taken to hopefully prevent loss of life from a similar type of fire in the future.
We conducted our study in the following way. We arrived in Charleston two days after the fire and began collecting as much data as possible about the store, its contents on the day of the fire, and the fire event itself. We gathered records about the building; video and photographs of the store before, during, and after the fire; radio transmissions from first responders during the fire; conducted informal discussions with store employees and interviews with firefighters; and reviewed other public materials describing the event.
Then we took all the data we collected and used it to generate a timeline of events and to simulate with a computer model developed at NIST the most probable sequence of fire behavior that matched well with the visual and other records available about what actually happened. With this computer modeling software, we can input data about many characteristics of a specific fire and then the model uses a set of rules based on what we know about the physics of fire to simulate changes in temperatures, oxygen levels, smoke, and other variables.
In your handout on page 5 you have the key events in the overall time line we constructed. It begins with the fire being observed at the rear of the store at 6:56 p.m. and continues to the collapse of the roof at 7:51 p.m. and finally to the fire being brought under control at 10 p.m.
With this timeline of the actual fire in place, we then created simulations of the fire behavior within the Sofa Super Store. First, we estimated what we call the fuel load, the type and amount of combustible material in the building. The fuel load in some furniture stores and especially those with large open display areas like the Sofa Super Store is higher than in most retail spaces. We estimated the energy content of the fuel load from foam-filled furniture in the showroom and loading dock areas of the Sofa Super Store to be about 610 gigajoules. For comparison, 100 gallons of gasoline contains about 12 GJ of energy.
We also created floor plans of the space based on our observations at the site, determined the materials used to construct the various parts of the building and whether sprinklers were present, established which doors and windows were open at what times to determine air and smoke flow, and gathered weather data. A key finding of this data gathering effort was the fact the store did not have automatic sprinklers.
Once we had described the conditions as accurately as possible, we ran several different simulations and matched them up against the photographs, videos, radio transmissions, interviews and other data available that described the Sofa Super Store fire. The simulation that best matched the available data is the most probable fire sequence. I will show several of these simulations in just a minute.
A technical computer simulation like this one is a science-based set of moving images that approximates how an event occurred. It is not identical to the actual event since we don't have all of the details of the store design and its contents or the computing power to include every detail about this fire, or any fire, in the model. It can, however, tell us with reasonable accuracy what temperatures were like at various times during the fire, how the fire moved over time, what the oxygen levels were at different times and locations in the building, and how much smoke was generated by burning furniture in the store and where it flowed.
The simulations we created to visualize the Sofa Super Store fire were, by necessity, complex and time consuming to run. Each simulation required about 4 days of computing time and the entire study required more than 250 separate runs.
While the fire engulfed both the store showrooms and the warehouse, our simulations did not include the warehouse since no firefighters were trapped in the warehouse and the fire in the warehouse did not directly affect the fire in the showrooms. In this slide, you see the layout of the building. The simulation runs at about 20 times normal speed. The data shown are for a slice of space about 5 feet above the floor.
This first simulation shows the change in temperature during the fire. [Narration of key changes in temperature as they appear in the simulation.]
This simulation shows how the smoke and fire moved during the fire. [Narration of key changes in smoke and fire as they appear in the simulation.]
This one shows changes in oxygen levels. Normal ambient air has about 21 percent oxygen. Previous research has shown that a person without oxygen from a breathing apparatus will have difficulty escaping if the air contains less than 12 percent oxygen. As this simulations runs, you will see changes in color indicating how the oxygen levels depleted as the fire progressed. [Narration of key changes in smoke and fire as they appear in the simulation.]
Based on the data we collected during this study and on these simulations I've just shown, as well as additional simulations available on the CD that is provided with our full report, we reached the following key findings:
The Sofa Super Store fire progressed at a rapid rate due to several important factors. These factors include:
The findings I've just described led us to several important recommendations:
First, furniture stores represent significant fire hazards and all state and local jurisdictions should adopt model building and fire codes that specifically address high fuel load commercial spaces.
Second, to ensure that hazardous conditions such as the lack of appropriate fire doors, fire walls, and sprinklers are identified and corrected, all state and local jurisdictions should implement aggressive fire inspection and enforcement programs and ensure that inspectors are professionally qualified to a national standard.
Third, all state and local authorities should adopt and enforce model codes that require automatic sprinkler systems for all new commercial retail furniture stores regardless of size and all existing furniture stores with any single display area greater than 2,000 square feet.
We also made several recommendations for additional research efforts that would further advance understanding of upholstered furniture flame spread, improved fire barriers, decision aids to help communities allocate their fire safety resources, ventilation of burning structures, and performance measures for fire protection.
When NIST issues a report of a fire study like this one, we often provide it in draft form so that comments from the public can be considered. We urge all parties to review the draft report and send us comments by Dec. 2 to email@example.com. Directions for submitting comments are provided on our web site at www.nist.gov.
In summary, the key lessons learned from our study are that a community's fire safety depends on the use and enforcement of model building and fire codes that address the specific hazards and fuel loads of different types of spaces. Furniture stores typically have large amounts of combustible material and represent a significant fire hazard. As a result, model building codes should require that both new and existing stores have automatic sprinklers, especially if those stores include large, open display areas.
Thank you. At this point we will be happy to take your questions.