Reserve Citizen Airmen firefighters from the 507th Civil Engineer Squadron at Tinker Air Force Base, Oklahoma, honor the fallen during the 9/11 fire climb Sept. 11, 2021, at the fire training tower. For the past 12 years during the September unit training assembly, Reserve firefighters at Tinker AFB have commemorated the victims of the attacks by climbing the fire tower for 56 minutes, the length of time the South Tower of the World Trade Center stood after it was struck. (U.S. Air Force photo by Tech. Sgt. Lauren Kelly)