An aerial view of the Muscatatuck Urban Training Complex taken during Exercise Vibrant Response near Camp Atterbury, Ind., Aug. 21. Muscatatuck is ground zero for all exercise scenarios, simulating a 10 kiloton nuclear device that was detonated in Cincinnati, Ohio. Vibrant Response is the largest chemical, biological, radiological and nuclear response exercise designed to prepare expeditionary units focused on responding to domestic CBRN incidents.