Senior Airman Max Hoagland, 28th Security Forces Squadron patrolman, guards a hallway as his team prepares to move during an active shooter exercise at Ellsworth Air Force Base, S.D., Aug. 12, 2014. The Airmen entered the 28th Communications Squadron headquarters to engage suspects, eliminate the threat to the base, assess casualties and report information to emergency responders. (U.S. Air Force photo by Senior Airman Zachary Hada/Released)