U.S. Marines attached to 3rd Platoon, A Company, 1st Battalion, 3rd Marine Regiment, "The Lava Dogs" enter through a window while conducting urban warfare training at Lava Viper aboard Pohakuloa Training Area, Hi., June 5, 2015. Marines hone in their skills of room clearing as well as increase their situational awareness during this exercise. (U.S. Marine Corps photo by Cpl. Ricky S. Gomez/Released)