Army National Guard Soldiers from the 738th Medical Company (Area Support) listen to role players ask for food and water during a mass decontamination exercise at the Muscatatuck Urban Training Center in Butlerville, Indiana, during exercise Guardian Response 21. Army Reserve and National Guard Soldiers, Engineers, chemical, biological, radiological and nuclear (CBRN) specialists, as well as medical units are conducting Defense Support of Civil Authorities (DSCA) training at the multi-million dollar facility to help prepare them to respond to a CBRN catastrophe at home or abroad. (Official U.S. Army Reserve photo by Sgt. 1st Class Brent C. Powell)