U.S. Airmen and Soldiers excavate a repair site during rapid airfield damage recovery (RADR) training at Osan Air Base, Republic of Korea, April 19, 2019. RADR is a quick process used to repair structural damages on an airfield where civil engineers evaluate damages, prepare areas for repair and pour concrete to get the airfield back to mission ready. (U.S. Air Force photo by Staff Sgt. Ramon A. Adelan)