U.S. Marines with Headquarters Battery, 5th Battalion,

U.S. Marines with Headquarters Battery, 5th Battalion, 11th Marine Regiment, 1st Marine Division, wear mission oriented protective posture (MOPP) suits with field protective masks during a decontamination training in support of Fire Exercise (FIREX) 2-18 at Marine Corps Base Camp Pendleton, Calif., April 23, 2018. FIREX 2-18 was a battalion level exercise designed to improve internal standard operating procedures and allow multiple batteries to train together. (U.S. Marine Corps photo by Lance Cpl. Alexa M. Hernandez)