On February 19, 2005, a 39-year-old career fire Captain (the victim) died after being trapped by the partial collapse of the roof of a vacant one-story wood frame dwelling. The house was abandoned and known by residents in the area to be a "crack house" at the time of the incident. The victim was the captain on the first-arriving engine crew which was assigned to perform a "fast attack" - to take a hoseline into the house, locate the seat of the fire, and begin extinguishment. The one-story wooden ranch-style house was built in the 1950s and additional rooms had been added at the rear in at least two phases following the initial construction. Crews arriving on scene could see fire venting through the roof at the rear of the house. The victim and a fire fighter advanced the initial attack line through the front entrance and made their way toward the rear of the house. Visibility was good in the front of the house but conditions quickly changed as they advanced toward the rear. The fast attack crew had just begun to direct water onto the burning ceiling in the kitchen and den areas when the roof at the rear of the structure (over the building additions) collapsed, trapping the captain under burning debris. The collapse pushed fire toward the front of the house which quickly ignited carbon and dust particles suspended in the air along with combustible gases, sending a fireball rolling toward the front of the structure. Prior to the time of the collapse, two other crews had entered through the front entrance. The rapidly deteriorating conditions following the collapse quickly engulfed the other crews with fire and five fire fighters received burns requiring medical attention. NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should: 1. ensure that the Incident Commander continuously evaluates the risk versus gain when determining whether the fire suppression operation will be offensive or defensive. 2. train fire fighters to communicate interior conditions to the Incident Commander as soon as possible and to provide regular updates. 3. use thermal imaging cameras (TIC) during initial size-up and search phases of a fire. 4. ensure fire fighters open ceilings and overhead concealed spaces as hoselines are advanced. 5. ensure that team continuity is maintained during fire suppression operations. 6. consider using exit locators such as high intensity floodlights or flashing strobe lights to guide lost or disoriented fire fighters to the exit. 7. train fire fighters on the actions to take while waiting to be rescued if they become trapped or disoriented inside a burning structure. Additionally, fire departments, municipalities and standard-setting bodies (such as the National Fire Protection Association (NFPA)) should consider developing and implementing a system to identify and mark dangerous and/or abandoned structures to improve fire fighter safety. Also, manufacturers, researchers, and designers as well as standard setting bodies (such as the NFPA) should consider ways to improve personal alert safety system (PASS) devices, radios, and other safety equipment to make them more effective in extreme fire conditions.