A man walks through a flood zone designed for training

A man walks through a flood zone designed for training during Guardian Response 17 at the Muscatatuck Urban Training Center, Indiana, April 27, 2017. Guardian Response, as part of Vibrant Response, is a multi-component training exercise run by the U.S. Army Reserve designed to validate nearly 4,000 service members in Defense Support of Civil Authorities (DSCA) in the event of a Chemical, Biological, Radiological and Nuclear (CBRN) catastrophe. This year's exercise simulated an improvised nuclear device explosion with a source region electromagnetic pulse (SREMP) out to more than 4 miles. The 84th Training Command is the hosting organization for this exercise, with the training operations run by the 78th Training Division, headquartered in Fort Dix, New Jersey. (U.S. Army Reserve photo by Master Sgt. Michel Sauret)