Airmen from the 779th Medical Group evaluate a simulated victim of a nuclear detonation to determine what sort of medical treatment he requires in exercise Vibrant Response at Camp Atterbury Joint Maneuver Training Center in Southern Indiana July 29. The exercise, hosted by U. S. Army North, U. S. Northern Command's Joint Force Land Component Command, brings together approximately 9,000 military and civilian personnel from across the country to simulate the response to a terrorist attack in the United States.