U.S. Marines attached to 1st Platoon, C Company, 1st Battalion, 3rd Marine Regiment - "The Lava Dogs" practice entering a room after breaching the door at Lava Viper aboard Pohakuloa Training Area, Hi., May 28, 2015. Combat Engineers and Assaultmen build different charges in order to breach through doors. (U.S. Marine Corps photo by Cpl. Ricky S. Gomez/Released)