U.S. Army Soldiers from the "Apocalypse," 3rd Battalion, 501st Aviation Regiment, 4th Brigade Combat Team, 1st Armored Division, react to a chemical attack outside the tactical operations center during a downed aircraft recovery team aviation exercise during Decisive Action Rotation 14-10 at the National Training Center Sept. 18, 2014. Decisive action rotation exercises provide a comprehensive approach to training Brigade Combat Teams in a joint, interagency, intergovernmental, and multinational environment. (U.S. Army photo by Spc. Ashley Marble, Operations Group, National Training Center)