On December 3, 1999, six career fire fighters died after they became lost in a six-floor, maze-like, cold-storage and warehouse building while searching for two homeless people and fire extension. It is presumed that the homeless people had accidentally started the fire on the second floor sometime between 1630 and 1745 hours and then left the building. An off-duty police officer who was driving by called Central Dispatch and reported that smoke was coming from the top of the building. When the first alarm was struck at 1815 hours, the fire had been in progress for about 30 to 90 minutes. Beginning with the first alarm, a total of five alarms were struck over a span of 1 hour and 13 minutes, with the fifth called in at 1928 hours. Responding were 16 apparatus, including 11 engines, 3 ladders, 1 rescue, and 1 aerial scope, and a total of 73 fire fighters. Two incident commanders (IC#1 and IC#2) in two separate cars also responded. Fire fighters from the apparatus responding on the first alarm were ordered to search the building for homeless people and fire extension. During the search efforts, two fire fighters (Victims 1 and 2) became lost, and at 1847 hours, one of them sounded an emergency message. A head count ordered by Interior Command confirmed which fire fighters were missing. Fire fighters who had responded on the first and third alarms were then ordered to conduct search-and-rescue operations for Victims 1 and 2 and the homeless people. During these efforts, four more fire fighters became lost. Two fire fighters victims 3 and 4) became disoriented and could not locate their way out of the building. At 1910 hours, one of the fire fighters radioed Command that they needed help finding their way out and that they were running out of air. Four minutes later he radioed again for help. Two other fire fighters (Victims 5 and 6) did not make initial contact with command nor anyone at the scene, and were not seen entering the building. However, according to the Central Dispatch transcripts, they may have joined Victims 3 and 4 on the fifth floor. At 1924 hours, IC#2 called for a head count and determined that six fire fighters were now missing. At 1949 hours, the crew from Engine 8 radioed that they were on the fourth floor and that the structural integrity of the building had been compromised. At 1952 hours, a member from the Fire Investigations Unit reported to the Chief that heavy fire had just vented through the roof on the C side. At 2000 hours, Interior Command ordered all companies out of the building, and a series of short horn blasts were sounded to signal the evacuation. Fire fighting operations changed from an offensive attack, including search and rescue, to a defensive attack with the use of heavy-stream appliances. After the fire had been knocked down, search-and-recovery operations commenced until recall of the box alarm 8 days later on December 11, 1999, at 2227 hours, when all six fire fighters' bodies had been recovered. NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should: ensure that inspections of vacant buildings and pre-fire planning are conducted which cover all potential hazards, structural building materials (type and age), and renovations that may be encountered during a fire, so that the Incident Commander will have the necessary structural information to make informed decisions and implement an appropriate plan of attack; ensure that the incident command system is fully implemented at the fire scene; ensure that a separate Incident Safety Officer, independent from the Incident Commander, is appointed when activities, size of fire, or need occurs, such as during multiple alarm fires, or responds automatically to pre-designated fires; ensure that standard operating procedures (SOPs) and equipment are adequate and sufficient to support the volume of radio traffic at multiple-alarm fires; ensure that Incident Command always maintains close accountability for all personnel at the fire scene; use guide ropes/tag lines securely attached to permanent objects at entry portals and place high-intensity floodlights at entry portals to assist lost or disoriented fire fighters in emergency escape; ensure that a Rapid Intervention Team is established and in position upon their arrival at the fire scene; implement an overall health and safety program such as the one recommended in NFPA 1500, Standard on Fire Department Occupational Safety and Health Program; consider using a marking system when conducting searches; identify dangerous vacant buildings by affixing warning placards to entrance doorways or other openings where fire fighters may enter; ensure that officers enforce and fire fighters follow the mandatory mask rule per administrative guidelines established by the department; explore the use of thermal imaging cameras to locate lost or downed fire fighters and civilians in fire environments; and in addition, manufacturers and research organizations should conduct research into refining existing and developing new technology to track the movement of fire fighters on the fireground.