U.S. Army National Guard and U.S. Air Force Air National Guardsman, assigned to the Chemical, Biological, Radiological, Nuclear Enhanced Response Force Package (CEREP), Ohio Army and Air National Guard, practice extracting victims who are trapped in the rubble of a collapsed building at Camp Atterbury, Indiana, on May 10, 2007, during Exercise Vigilant Guard, a joint military and civilian training exercise simulating the detonation of nuclear devices in a metropolitan area. (U.S. Army photo by STAFF SGT. Russell Lee Klika) (Released)