US | Hawthorne Army Depot 7 Marines Dead in Explosion at Nev. Army Depot Another 8 wounded during training exercise accident By Evann Gastaldo Posted Mar 19, 2013 7:58 AM CDT Updated Mar 19, 2013 8:20 AM CDT Copied Soldiers from Operational Detachment Alpha 3133 conduct a mounted-dismounted route clearing exercise during a pre-mission training exercise at the Hawthorne, Nev., Army Depot on Oct. 6, 2008. (AP Photo/U.S. Army, Staff Sgt. Corey T. Dennis) Seven US Marines are dead after an explosion at Hawthorne Army Depot in Nevada last night, military officials tell NBC News. The accident occurred at an ammunition storage facility during a live-fire training exercise, when a 60-millimeter mortar exploded in a tube as Marines were getting ready to fire it. Another eight Marines were wounded; three are in serious condition. The 147,000-acre depot is used for storing and destroying demilitarized ammo, Reuters reports. Read These Next Updated list of free days at national parks is raising some eyebrows. An incredible hush-hush effort saw 55 cartel bosses brought to the US. Many people quietly struggle with pelvic floor dysfunction. After Quentin Tarantino blasts actors, one responds. Report an error