Senior Airman Derek Asbury, 509th Maintenance Group, is transported into the back of an ambulance during an active-shooter exercise at Whiteman Air Force Base, Mo., Feb. 11, 2015. The Johnson County Ambulance District, from Warrensburg, Mo., also participated as local-civilian first responders during the exercise. (U.S. Air Force photo by Airman 1st Class Joel Pfiester/Released)