U.S. Air Force Airmen with the 455th Expeditionary Aerial Port Squadron listen to Check Six program training instructions at Bagram Airfield, Afghanistan Oct. 21, 2014. Airmen recently participated in the training, which is intended to help increase Airmen’s awareness and vigilance in case of an active shooter event. (U.S. Air Force photo by Staff Sgt. Evelyn Chavez/Released)