HAWTHORNE, Nev. -- Seven Marines from a North Carolina unit were killed when a 60mm mortar exploded unexpectedly at a Nevada military depot that's an important training facility for troops headed overseas, a Marine Corps official said.
The Marines immediately issued an indefinite moratorium on firing of all such mortars worldwide until an investigation clears as safe the type of weapon and ammunition in the tragedy. Several other Marines from the 2nd Marine Expeditionary Force at Camp LeJeune, N.C., were hurt in the accident shortly before 10 p.m. PDT Monday at the Hawthorne Army Depot.
The official, speaking on condition of anonymity, said it was not immediately clear whether the mortar exploded prematurely inside its firing tube or whether more than a single round exploded. The official was not authorized to speak to a reporter about the accident.
The 60mm mortar is a weapon that traditionally requires three to four Marines to operate, but it's common during training for others to observe nearby.
Renown Regional Medical Center in Reno, the area's major trauma hospital, took nine patients, including one who died, three who are in serious condition and five who are in fair condition, according to spokeswoman Stacy Kendall. All the patients are men under the age of 30, she said. Kendall described their injuries as penetrating trauma, fractures and vascular injuries.
The identities of those killed won't be released until 24 hours after their families are notified.
"We send our prayers and condolences to the families of Marines involved in this tragic incident. We remain focused on ensuring that they are supported through this difficult time," said the force's commander, Maj. Gen. Raymond C. Fox. "We mourn their loss, and it is with heavy hearts we remember their courage and sacrifice."
The Marine Corps official said it was unclear why the mortar exploded unexpectedly or whether the shell exploded before it had been expelled from its firing tube. An explosion at the point of firing in a training exercise could kill or maim anyone inside or nearby the protective mortar pit and could concussively detonate any mortars stored nearby in a phenomenon known as "sympathetic detonation."
The official did not know whether the seven dead Marines and several others who were hurt were in the same firing pit, standing nearby for training observation or in an adjoining mortar pit, but any of those situations would have been them in danger after such an explosion.
The official said a worldwide moratorium after such an accident is not unusual and would persist until the investigation determines that the weapon did not malfunction in ways that would hurt other Marines or that mortars manufactured at the same time as the one involved in the accident were safe to continue to use. The official said it would be normal to warn other U.S. military branches that use 60mm mortars, such as the Army, about the Marines warning. The moratorium could last for weeks or months.
The investigation will focus on whether the Marines followed procedures to properly fire the weapon, whether there was a malfunction in the firing device or in the explosive mortar itself, the official said.
The Hawthorne Army Depot stores and disposes of ammunition. The facility is made up of hundreds of buildings spread over more than 230 square miles.
Hawthorne has held an important place in American military history since World War II when it became the staging area for ammunition, bombs and rockets for the war. The Nevada Division of Environmental Protection says that the depot employed more than 5,500 people at its peak. Nevada was chosen for the location because of its remoteness in the wake of a devastating explosion at the government's main depot in New Jersey in the 1920s.
It opened in September 1930 as the Naval Ammunition Depot Hawthorne and was redesignated Hawthorne Army Ammunition Plant in 1977 when it moved under the control of the Army, according to its website. In 1994, the site ended its production mission and became Hawthorne Army Depot. The site currently serves several purposes for the military, including storing ammunition and explosives and providing what the military calls an ideal training facility for special forces preparing for deployments to similar desert terrain in places like Afghanistan.
Nevada and North Carolina political leaders expressed their sympathy.
Senate Majority Leader Harry Reid, D-Nev., gave his condolences to victims of the explosion during a Tuesday morning speech on the Senate floor. "My thoughts are with those who were injured. My heart goes out to the families of those who lost their lives. And my sympathies are with their fellow Marines, who are also grieving this loss."
Nevada Republican Sen. Dean Heller tweeted, "Thoughts and prayers are with the families who lost a loved one in the Hawthorne Army Depot explosion. Grateful for their service."
"The men and women who work and train there put service ahead of self each and every day," Republican Nevada Gov. Brian Sandoval said in a statement. "Kathleen and I wish to extend our deepest sympathies to those killed and their families. Our thoughts and prayers are with those who have been injured and we pray for their speedy recovery."
"I was so saddened to learn about the seven Marines from Camp Lejeune who were killed last night in Nevada," U.S. Sen. Kay Hagan, D-N.C., said in a statement. "My thoughts and prayers are with the families of the Marines who were killed and those who were injured, and I will continue to monitor the investigation so we can find out what happened and take appropriate steps."