Abstract: At 2:06 a.m. on December 16, 2021, Engine 94 responded to a multi-family dwelling fire and operated between the arrival time of 2:11 a.m. until the clear time of 5:13 a.m. During the operation, firefighters were instructed to attack the seat of the fire, however the conditions deteriorated rapidly as the members prepared to enter the building. Employee #1 approached the building with his partner behind him, but he entered alone and was separated from the crew without contact. Employee #1 was later found unconscious after a member heard a mayday request. Employee #1 was admitted to the hospital for injuries sustained, and later died due to thermal injuries, smoke inhalation, and pulmonary and cerebral edema. An investigation was immediately launched to determine the root cause of the incident. Upon entering the upper level of the building, Firefighter #4 of Engine B heard a Personal Alert Safety System (PASS) alarm and crawled towards it, where he found Employee #1 face down in the dining room, approximately 20 feet into the unit. He did not see him on the Thermal Imagining Camera and assumed that his bunker gear was hiding his heat signature on the camera. He also indicated that although the PASS alarm was sounding, there were no bells, nor was there air flowing from his SCBA. According to the transcripts received, Employee #1 transmitted a mayday call at approximately 2:18 a.m., and at around 2:31 a.m., they were removing him from the area where he was found.