Abstract: At 11:04 p.m. on December 3, 2021, a resident called 911 to report a structure fire in a garage. The Fire Department arrived on the scene at 11:18 p.m. The fire spread to the home and offensive firefighting measures were employed as firefighters concentrated on removing the ceiling. The employee and Coworker #1 teamed up and entered the living room and began to pull the ceiling down with Coworker #2 on nozzle. They exhausted their air bottles and left to swap out bottles and be reassigned. The employee and Coworker #1 entered the building again together. Coworker #2 was entered to meet up with Coworker #3 and Coworker #4, who reported low visibility due to heavy smoke. Coworker #1 entered the first bedroom and started to pull the ceiling while the employee went to the last bedroom on the left and Coworker #2 went to the bathroom to do the same. Coworker #1 and Coworker #2 exhausted their air bottles and exited. As they exited, the ceiling trusses came down and they informed Operations Command. The employee walked into the kitchen and spoke with Coworker #5. The employee was low on air and left the room alone. The fire entered the room and they heard a Mayday on the primary channel. They tried to determine who was calling for help and with no answer heard a second Mayday with no response. The operations commander requested a Personal Accountability Report (PAR). No officer took credit for declaring PAR was completed; however, multiple firefighters heard "We have PAR" on the radio. Coworker #3 and Coworker #4 conducted an interior search of the 1st floor and found nothing. Another crew cut holes to access to the basement while another crew attempted to gain access through the stairs, but the passageway was blocked. They ran low on air and exited. About this time,they discovered the employee missing and began to search for the downed firefighter. The employee was located in the basement and had died due to lack of oxygen and inhalation of products of combustion.