JOINT BASE LANGLEY-EUSTIS, Va. –
An individual, posing as a casualty, lays in front of the 633rd Civil Engineer Squadron customer service desk during an active shooter exercise at Joint Base Langley-Eustis, Va., Dec. 15, 2016. During the exercise, four individuals were confirmed deceased and six injured after a disgruntled customer attacked personnel in the building. (U.S. Air Force photo by Senior Airman Kimberly Nagle)