Report reveals cause of Hawthorne mortar blast

A Marine loads a 60 mm mortar during training at Hawthorne Army Depot,  in July 2011. A military investigation into the deadly mortar accident at HAWD  10 months ago concludes the explosion resulted from human error, due in part to inadequate training and some Marines' lack of familiarity with the weapons system.

A Marine loads a 60 mm mortar during training at Hawthorne Army Depot, in July 2011. A military investigation into the deadly mortar accident at HAWD 10 months ago concludes the explosion resulted from human error, due in part to inadequate training and some Marines' lack of familiarity with the weapons system.

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A report released Wednesday on one of the deadliest military accidents in Nevada stated a double-loaded round dropped into a mortar tube caused the deaths of seven Marines and wounded eight others 10 months ago at the Hawthorne Army Depot.

The Marines from 1st Battalion, 9th Marine Regiment, 2nd Marine Division, II Marine Expeditionary Force from Camp Lejeune, N.C., were conducting night-time live-fire and maneuver training at HAWD on March 18. Care Flight helicopters transported the injured to Renown Regional Medical Center in Reno for treatment.

The Marine Corps Times obtained the complete report after filing a Freedom of Information Act request.

The military investigation revealed that both human error and a lack of some Marines’ familiarity with the 60-mm mortar led to the explosion. The report further stated that a lack of training was another cause for the accident. The 19-page report also revealed that the Marines had closely grouped the mortars, and that they had successfully fired numerous rounds before the blast.

Before the fatal explosion, the report said a Marine loaded a shell into the mortar after a shell already in the tube had detonated. The action resulted in the ejection of a half-loaded round before the fatal incident occurred.

The names of the fallen Marines were Pfc. Joshua M. Martino, 19, of Clearfield, Pa.; Lance Cpl. David P. Fenn II, 20, of Polk City, Fla.; Lance Cpl. Roger W. Muchnick Jr., 23, of Fairfield, Conn.; Lance Cpl. Joshua C. Taylor, 21, of Marietta, Ohio; Lance Cpl. Mason J. Vanderwork, 21, of Hickory, N.C.; Lance Cpl. William T. Wild IV, 21, of Anne Arundel, Md.; and Corporal Aaron J. Ripperda, 26, of Madison, Ill.

The report stated several Marines died on their way to Reno aboard a medical helicopter.

A day after the explosion, Hawthorne residents gathered at a park for a candlelight vigil to remember both the deceased and injured Marines. A Navy corpsman was among those injured. A private memorial service for family and unit members was conducted a month later at Camp Lejeune.

Before conducting their training at HAWD, the Marines had been deployed to Kuwait and upon their return to the Untied States, they spent time at the Marine Corps Mountain Warfare Training Center near Bridgeport, Calif.

In the report, investigators attributed four factors to the explosion including inadequate training, improper gunnery commands and firing procedures, a “perceived sense of urgency and resultant haste” within the mortar section and systemic lack of supervision leading up to and during the exercise. Investigators further ruled the accident was not “the result of misconduct on the part of any victims.”

The Marines, according to the report, were more accustomed to firing the larger 81-mm mortar that doesn’t have a trigger and is impossible to double load.

Investigators compiled pages of information and documentation and conducted 28 interviews beginning with then-battalion commander Lt. Col. Andrew McNulty. A command investigation report released in May 2013 stated McNulty; Capt. Kelby Breivogel, commander of Alpha Company; and Chief Warrant Officer 3 Douglas Derring, the battalion’s gunner, were relieved of their commands by Brig. Gen. James Lukeman, commanding general of 2nd Marine Division, the battalion’s parent command.

According to a Marine Corps spokesman at the time, the three were allowed to remain in the service, but their next duty assignments were unknown.