A Marine with 2nd Battalion, 6th Marine Regiment, 2nd Marine Division, II Marine Expeditionary Force throws a grenade into a building during a training exercise at MOC-3 range aboard Marine Corps Base Camp Lejeune, N.C., Oct. 21, 2014. The Marines spent hours preparing for their live-fire event, honing their teams to communicate from the point of entry into the building and on through rooms filled with enemy targets.