SPONGE BATH U.S. Army soldiers sponge off their level A suits after a simulated nuclear detonation scenario during exercise Vibrant Response on Muscatatuck Urban Training Center, Ind., July 19, 2010. The soldiers are assigned to the 457th Chemical Battalion. The U.S. Northern Command training event focused on chemical, biological, radiological, nuclear and high yield explosives. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 405038-N-GZU34-820.jpg Photo Gallery