A U.S. Air Force fire team assigned to the 633rd Security Forces Squadron runs to increase their heart rate during active shooter training at Langley Air Force Base, Va., Oct. 28, 2014. The Airmen performed various exercises before loading their weapons with simulation rounds and advancing toward an active shooter. (U.S. Air Force photo by Senior Airman Kayla Newman/Released) (Photo was cropped, levels, contrast and sharpening was used to emphasis subject.)