U.S. Army Sgt. 1st Class Bryan Whyard, military policeman with the 193rd Military Police Battalion, Colorado Army National Guard, controls access to the ambulance bay of Exempla St. Joseph Hospital in Denver, Colo., July 23, 2013, during a natural-disaster training scenario decontamination exercise as part of the 2013 Vigilant Guard exercise. Vigilant Guard, hosted by the Colorado National Guard, is a large-scale, multi-state, multi-agency exercise focused on inter-agency coordination in preparation for emergencies and catastrophic events in Colorado. (U.S. Army National Guard photo by Spc. Zach Sheely/RELEASED)