The names of the deceased Marines are:
Staff Sgt. Mathew R. Marsh, 28, of Long Beach, Calif., an Explosive Ordnance Disposal Technician. He deployed twice to Iraq in 2005 and 2008 and twice to Afghanistan in 2010 and 2012 as a team leader.
Gunnery Sgt. Gregory J. Mullins, 31, of Bayou L'Ourse, La., was the Explosive Ordnance Disposal Staff Noncommissioned Officer-in-Charge. He deployed twice to Afghanistan in 2011 and 2012 as a team leader.
Sgt. Miguel Ortiz, 27, of Vista, Calif., was an Explosive Ordnance Disposal Technician. He deployed to Iraq in 2007, to the Western Pacific in 2008 and to Afghanistan in 2012.
Staff Sgt. Eric W. Summers, 32, of Poplar Bluff, Mo., was an Explosive Ordnance Disposal Technician. He deployed to Kuwait in 2003, Iraq in 2004 and three times to Afghanistan in 2009, 2011 and 2012 as a team leader.
The Zulu impact area is used for firing explosive munitions such as grenades, mortars, artillery and rockets and for dropping munitions from aircraft. While live-fire training was ongoing at the adjacent Whiskey impact area, there was no live-fire training being conducted Wednesday in the Zulu area, according to a Marine Corps news release.
The cause of the accident was under investigation.