U.S. Air Force Master Sgt. Scott Wagonblott, 633rd Communications Squadron information assurance manager, takes cover behind a vehicle during an active-shooter exercise at Langley Air Force Base, Va., Nov. 19, 2013. The simulation tested Airmen from multiple organizations, including the 633rd Medical Group, 633rd Civil Engineer Squadron and 633rd Security Forces Squadron. (U.S. Air Force photo by Airman 1st Class Victoria H. Taylor/Released)