One Marine was killed and 21 others were injured Sunday after a United States military aircraft — a Bell Boeing V-22 Osprey — crashed on landing during a training exercise in Honolulu, Hawaii.

According to U.S. Marine Corps Forces Pacific spokesman Capt. Alex Lim, the injuries ranged from critical to minor.

The “hard-landing mishap” occurred around 11:40 a.m. at Bellows Air Force Station on Oahu, the 15th Marine Expeditionary Unit said in a statement.

The Osprey is a tilt-rotor aircraft that flies like a plane but takes off and lands like a helicopter.

One Navy corpsman and 21 Marines were onboard at the time of the accident.

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The unit is based at Camp Pendleton in California and is in Hawaii for about a week of training. The Osprey was being used for training at the time of the crash, the cause of which was under investigation, Lim said.

Kimberly Hynd said she was hiking the popular Lanikai Pillbox Trail and could see three Osprey aircraft performing maneuvers from her vantage point in the hills above the base.

She noticed them kicking up dirt but then saw smoke and fire. Hynd, who estimated she was 2 to 3 miles away, didn’t hear the sound of a large crash.

“It looked like they were doing some sort of maneuver or formation — and so I was taking pictures of it because usually you can’t see them that close up,” Hynd said.

Donald Gahit said he looked outside his house after hearing sirens pass by and saw smoke rising from the air station.

“At first I thought it was clouds, but it was moving fast and it was pretty dark,” the Waimanalo resident said.