U.S. Marine Corps Lance Cpl. Michael Hallam, left, and Lance Cpl. Eric Hull, right, both riflemen with Kilo Company, 3rd Battalion, 25th Marine Regiment, 4th Marine Division, prepare to breach a bunker by throwing in a grenade during a simulated exercise of clearing a trench during Integrated Training Exercise 4-19 aboard the Marine Corps Air Ground Combat Center, Twentynine Palms, Calif., June 5, 2019. ITX measures a unit’s ability to provide a cohesive, trained, and ready capability in support of service and Combatant Commander requirements. (U.S. Marine Corps photo by Lance Cpl. Preston L. Morris)