The Marine Corps Times is reporting that last year's deadly Hawthorne Army mortar explosion was the result of a double-loaded round.

Authorities say the March 18th accident occurred when a 60 millimeter mortar tube exploded during a field exercise. Seven Marines were killed in the incident and eight others were wounded.

The newspaper says the 19-page investigation reported that human error was to blame along with lack of training and added that some of the servicemen weren't familiar with the weapons system.

Marine spokesman Lt. Adam Flores told The Associated Press that the investigation found the explosion was triggered when a Marine dropped a second round into an already loaded mortar tube during a live-fire exercise.

Two officers and a noncommissioned officer were relieved of command following the explosion.

All of the servicemen were based at Camp Lejeune, North Carolina.

The names of the fallen warriors are Private First Class 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 names of the injured are Pfc. James P. Davies, Pfc. Trent M. Martin, Lance Cpl. Sean J. Burke, Lance Cpl. Douglas L. Hand II, Lance Cpl. Myles E. Harris, Petty Officer 3rd Class Ian S. McClanahan, Sgt. Caleb W. Patton, and Chief Warrant Officer 2 Ryan P. West. 

The Marine Corps Times says it obtained the report through the Freedom of Information Act.