Marine Military Helicopter MV-22 Osprey crash 1 dead 12 injured May 17, 2015

A Marine was killed when a military helicopter carrying 22 people went down Sunday at Bellows Air Force Base, Hawaii, the Marine Corps said.

The Marine Corps said in a brief statement that 22 people were aboard the MV-22 Osprey from the 15th Marine Expeditionary Unit when it had a "hard-landing mishap" during a training exercise. It gave no cause for the incident.

The Marines initially said 12 Marines were injured. After confirming the death, it said only that all 21 of the others had been taken to hospitals for assessment and treatment.

Witnesses told NBC station KHNL of Honolulu that the nearby beach was very busy when the chopper went down, with at least 3 aircraft doing rotations in the sky.

The witnesses watched the 3 aircraft swoop toward the ground — but only 2 came back up. Within seconds, black smoke could be seen, they said.

The 15th MEU is based at Camp Pendleton in San Diego. The Marines who were invloved in the incident Sunday arrived May 10 in Hawaii for a 7-month deployment, the service said Sunday night.