On February 18, 2004, a 40-year-old male career fire fighter (the victim) was fatally injured in a commercial restaurant/lounge structure fire. The victim, providing mutual aid, had been searching for the seat of the fire with two volunteer fire fighters from another department, when one of these fire fighters lost the seal on his self contained breathing apparatus (SCBA) face piece. The fire fighter immediately abandoned the nozzle position and retreated out of the closest door. The backup fire fighter also retreated out of the building when his partner left. In the black smoke and zero visibility, the fire fighters were unaware that the victim was still inside the structure. Soon after, the Incident Commander (IC) ordered an emergency evacuation because of an imminent roof collapse, and an air horn signal was sounded. Personnel accounting indicated that a missing fire fighter (the victim) was still inside the building when the roof partially collapsed. After several search attempts, the victim was found in a face-down position with his mask and a thermal imaging camera cable entangled in a chair. His facemask was dislodged and not over his mouth. He was pronounced dead on scene. NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should: 1. conduct pre-incident planning and inspections to facilitate development of a safe fire ground strategy; 2. review, revise where appropriate, implement, and enforce written standard operating guidelines (SOGs) that specifically address: incident command (IC) duties, emergency evacuation procedures, personnel accountability, rapid intervention teams (RIT) and mutual aid operations on the fireground; 3. train on the SOGs, the incident command system, and lost fire fighter procedures with mutual aid departments to establish interagency knowledge of equipment, procedures, and capabilities; 4. ensure that the IC maintains the role of directing fireground operations for the duration of the incident or until the command role is formally passed to another individual; 5. ensure that the IC conducts a risk-versus gain analysis prior to committing fire fighters to the interior and continually assesses risk versus gain throughout the operations; 6. consider appointing a separate, but systematically integrated incident safety officer; 7. ensure that all fire fighters are equipped with radios capable of communicating with the IC; 8. ensure personnel accountability reports (PAR) are conducted in an efficient, organized manner and results are reported directly to the IC; 9. revise and enforce policies and guidelines regarding activation of personal alert safety systems (PASS) devices; 10. ensure that fire fighters train with thermal imaging cameras (TIC) and they are aware of their proper use and limitations; 11. ensure that individual fire fighters are trained and aware of the hazards of exposure to carbon monoxide and other toxic fire gases.