U.S. Air Force Staff Sgt. Geoffrey Range, 633rd Civil Engineer Squadron firefighter, instructs a group of evacuees during a simulated chemical, biological, radiological, nuclear and high-yield explosive threat during an exercise at Langley Air Force Base, Va., March 26, 2015. The exercise tested Joint Base Langley-Eustis personnel’s ability to respond to preplanned, indiscriminate use of CBRNE weapons aimed the installation. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)