Copyrighted Image? DMCA | Seven U.S. Marines were killed and at least seven wounded when a mortar exploded during a live-fire training exercise overnight at an Army munitions depot in the Nevada desert, military officials told NBC News. The accident happened just before 10 p.m. Monday at Hawthorne Army Depot, a 230-square-mile ammunition storage and training facility just east of the California line. The Marines were part of the 2nd Marine Division, a ground combat force based at Camp Lejeune, N.C. |