U.S. Airmen assigned to the 51st Security Forces Squadron perform a human wheel barrel during the 2019 Defenders’ Challenge at Osan Air Base, Republic of Korea, May 22, 2019. In honor of police week, the 51st SFS held various events to pay tribute to law enforcement members who have fallen in the line of duty. Teams of four endured seven courses testing their physical, mental and social fitness during the challenge. (U.S. Air Force photo by Staff Sgt. Sergio A. Gamboa)