A Marine from Marine Forces Reserve secures the perimeter of a contaminated area during a chemical, biological, radiological and nuclear defense training simulation aboard Naval Air Station Joint Reserve Base New Orleans, Feb. 5, 2015. Marines with the survey team are responsible for securing the perimeter and extracting any casualties. The CBRN defense training equips Marines from diverse units, with the proper knowledge and readiness needed to handle a real combat zone situation. (U.S. Marine Corps photo by Lance Cpl. Ian Ferro)