A new National Institute of Standards and Technology (NIST) computer-modeling study of a 2012 Chicago house fire reveals the conditions that unleashed a surge of searing gases, leading to the death of a veteran firefighter.
NIST examined the fire dynamics of the incident at the request of the National Institute for Occupational Safety and Health (NIOSH) and the Chicago Fire Department. Simulations conducted with NIST's Fire Dynamics Simulator examined the fire's temperature and pressure at various locations and the resulting flow path. With the agency's Smokeview visualization software, NIST researchers also developed a graphical representation of the fire's behavior and the conditions that firefighters likely experienced during the course of their interior operations.
The simulation shows that fire in a covered back porch caused a closed steel-faced, wood-framed door to crumble, releasing pressure and causing hot gases to pour into the adjoining hallway where the victim and another firefighter were advancing a fire hose. The coincidental timing of the responders' "interior attack" and the door's failure proved to be deadly. In less than 5 seconds, the flow of gases caused the hallway temperature to soar, from about 60 degrees Celsius (140 degrees Fahrenheit) to at least 260 degrees Celsius (500 degrees Fahrenheit), the study found.
The victim, a 54-year-old captain, was overwhelmed by the rush of fire gases. He was removed to the exterior, revived by paramedics, and transported to a hospital, where he died.
The study is published as a NIST report* as well as a video summary. These research outputs "provide a clear start-to-finish analysis of a tragic, real-life fire event," says Donald Hroma, district chief in the Safety Division of the Chicago Fire Department. "They afford a very useful perspective. The Chicago Fire Department and others across the country will use these tools in training and to inform decisions on how to improve the ways we approach and attack fires."
Since 1999, NIOSH has issued reports on 15 fires in which changes in flow paths have resulted in 17 "line-of-duty" deaths of firefighters, in addition to civilian deaths and injuries to responders. Failure of a door or window, collapse of a ceiling, and uncoordinated ventilation during a firefighting operation are among the variety of factors that can rapidly alter a fire's flow path.
Including the Chicago tragedy, NIST has used its Fire Dynamics Simulator to study six fires that have resulted in firefighter deaths. Insights into fire behavior and thermal conditions gleaned from these studies have helped to shape research aimed at improving the safety and effectiveness of firefighters.
Recent NIST research, conducted with Underwriters Laboratories, several fire departments, and other organizations, demonstrates that applying water from the exterior of a burning structure—before attacking the fire from the inside—can reduce the potential for high-speed flows of hot gases to develop and ignite.