Abstract: At 6:00 a.m. on November 13, 2023, a firefighting crew responded to a building fire. Engine 55 performed suppression operations, while Truck 44 (T44) performed forcible entry and ventilation operations. A crew of two from T44, including Firefighter 1, went to the flat roof of the four-story building to perform vertical ventilation. A crew of two from Squad 1 joined the crew to assist in ventilation operations. Firefighters operating on the roof identified two light shafts covered in corrugated plastic. The plastic covering over one shaft was removed by a firefighter to aid in ventilation. The firefighter left a flashlight near the open shaft to identify the location and announced this. The T44 crew used a power saw and axe to open the roof for additional ventilation. A firefighter on the T44 roof crew asked a firefighter from the Squad 1 crew where the other crew member (Firefighter 1) from T44 was. The firefighter from Squad 1 looked down the open shaft and heard a firefighter distress alarm sounding (PASS). This was communicated to command and a mayday response was requested by the incident commander. Firefighter 1 fell down one of two light shafts to the basement of the four-story building. Firefighter 1 struck I-beams that spanned the floors and landed on his back/bottle. Due to limited access, crews determined that it would be best to breach the light shaft on the second floor, descend to package Firefighter 1, and raise him to an opening that was breached on the first floor. Firefighter 1 remained conscious until the time he was removed from the shaft and placed on the cot. Lifesaving efforts commenced and Firefighter 1 was transported to a hospital, but he died from his injuries. The cause of death was multiple blunt force injuries due to a fall from height.