First Lieutenant Kevin Zimmerman, a platoon commander

First Lieutenant Kevin Zimmerman, a platoon commander with Company K, 3rd Battalion, 7th Marine Regiment, 1st Marine Division radios in the enemy’s location while wearing a gas mask during a simulated chemical attack aboard Maine Corps Air Ground Combat Center Twentynine Palms, Calif., June 6, 2016. The chemical attack was part of the battalion’s Marine Corps Combat Readiness Evaluation and helped prepare the Marines for an upcoming deployment with the Special Purpose Marine Air-Ground Task Force – Crisis Response – Central Command later this year.(U.S. Marine Corps photo by Lance Cpl. Timothy Valero/ Released)