PHOTOS: Explosion in northern Nevada kills 7 Marines 

Seven Marines are dead after an explosion in northern Nevada caused by a military training exercise gone wrong.

  • Seven Marines are dead after an explosion in northern Nevada caused by a military training exercise gone wrong.

  • Two other Marines and a Sailor were critically injured. Four other Marines were seriously injured, and at least one Marine suffered minor injuries.

  • It will be at least 24 hours before the identities of those killed are released.

  • The incident happened late Monday night at the Hawthorne Army Depot, located in a rural area southeast of Reno.

  • A mortar round exploded in the mortar tub," said Brigade General James Lukeman. "We don't know yet what caused the malfunction."

  • For years, units have traveled to the depot in the Nevada desert because of its remote location and terrain, which is comparable to the terrain in the Middle East. It spans 147,000 acres.