Human error blamed in Hawthorne explosion that killed seven Marines

Human error has been cited as the cause of a mortar explosion that killed seven Marines and injured eight other service members in Hawthorne on March 18.

Results of the investigation were released this morning in a statement issued by the 2nd Marine Division.

The deaths and injuries occurred during a live-fire night attack at the Hawthorne Army Depot, when a 60mm mortar round exploded in the vicinity of the mortar section’s firing position, said Marine spokesman 1st Lt Peter Koerner.

The Marines using one of the mortars did not follow correct procedures, resulting in the detonation of a high explosive round at the mortar position, he said.

The investigation also determined that the mortar section hadn’t done appropriate preparatory training leading up to the live-fire event.

A command investigation was initiated immediately after the incident by Brig. Gen. James Lukeman, the commanding general of 2nd Marine Division.

As a result of the investigation’s findings, Lukeman relieved Lt. Col. Andrew McNulty, the commanding officer of 1st Battalion, 9th Marines, on May 8.

Capt. Kelby Breivogel, the company commander of Company A, and Chief Warrant Officer 3 Douglas Derring, the battalion’s Marine infantry weapons officer were also relieved of their duties.

Lukeman relieved those officers because he lost trust and confidence in their ability to ensure proper preparation for, and conduct of, live-fire training events, according to Koerner

Lt. Col. Corey Collier assumed command of 1st Battalion, 9th Marines, on May 23.

No Marines or sailors have been charged with a crime or violation of the Uniform Code of Military Justice and no charges are anticipated.

The investigation also determined that the mortar system functioned properly at Hawthorne and found no reason to question the safety of the system when it is employed as designed and as Marines are trained to employ it.