Wreckage, flames and smoke serve as the aftermath of a simulated 10-kiloton nuclear detonation at Muscatatuck Urban Training Complex near Camp Atterbury, Ind., on Aug. 16, 2011, during Vibrant Response 12. U.S. Army North conducted the exercise to prepare military forces for their role in responding to a catastrophic chemical, biological, radiological or nuclear incident in the homeland. (U.S. Army photo by Staff Sgt. Keith Anderson)