CAMP PENDLETON - An explosion that killed four Marines at Camp Pendleton last fall likely occurred when a service member accidentally mishandled a piece of ordnance, according to military investigative results released Thursday.
In light of the findings, the officer and staff non-commissioned officer in charge of the base explosive-ordnance disposal section were relieved from duty this week by Brig. Gen. John Bullard, commander of Marine Corps Installations West, according to a statement from the Oceanside-area USMC installation.
The stated reasons for removing the squad leaders from their posts Tuesday were "loss of trust and confidence in their ability to ensure proper preparation for and conduct of EOD proficiency training and lack of adherence to the established norms."
A base spokesman said regulations precluded him from releasing the names of the officers who lost their assignments due to the explosion.
The Nov. 13 blast claimed the lives of Sgt. Miguel Ortiz, 27, of Vista; Staff Sgt. Mathew R. Marsh, 28, of Long Beach; Gunnery Sgt. Gregory J. Mullins, 31, of Bayou L'Ourse, La.; and Staff Sgt. Eric W. Summers, 32, of Poplar Bluff, Mo.
Two other Marines and a Navy corpsman suffered non-fatal injuries in the accident.
The detonation occurred while personnel were sweeping an artillery range for unexploded munitions.
"The investigation established that the exact cause of the explosion is indeterminate, as the only individuals with direct observation are deceased," according to the statement. "Based on the findings of the investigation, the most probable cause of the explosion is a M430/A1 40 mm high- explosive dual-purpose round was dropped, kicked or bumped in the demolition pit."
USMC officials were "deeply saddened by the tragic loss" of the personnel during their "inherently dangerous" training at Camp Pendleton, Bullard said. "Their loss is felt throughout the Marine Corps."