The investigation into the cause of a helicopter crash in Norway that killed four Marines have been completed and released, according to yourradioplace.

On March 18, a crash took place during a training exercise, killing 30-year-old aerial observer Gunnery Sergeant James W. Speedy of Cambridge, Ohio, and three other Marines.

The 2nd Marine Aircraft Wing unit released a statement saying that a series of maneuvers at a low altitude exceeded the maximum angle-of-bank of the aircraft and was the primary reason for the crash, reported yourradioplace.

The investigation concluded that the cause of the accident was pilot error.

Other factors that the report considered were weather, training, maintenance, and terrain.

The report stated that the crew refueled and departed for its authorized flight but ran into trouble shortly after takeoff, which resulted in the crash.

Gunnery Sgt. James Speedy joined the Marines in June of 2009 serving as an administrative specialist and received many decorations including the Navy and Marine Corps Achievement Medal with two gold stars.