3 Marines were killed and 20 injured after a US helicopter crashed on a training exercise in northern Australia

• Three Marines died when a US military helicopter crashed in northern Australia.
• Five others are in a serious condition in hospital after the Boeing MV-22B Osprey crashed.

Three Marines were killed when a US military helicopter carrying 23 people crashed in northern Australia.

A representative for the US Marines told Insider that a Boeing MV-22B Osprey tilt-rotor aircraft went down during a training exercise at about 9.30 a.m. Sunday local time.

All 20 remaining survivors sustained injuries in the crash, and five are in hospital in a serious condition.

According to a statement, the troops were taking part in a training exercise involving 2,500 personnel from the US, Australia, the Philippines, East Timor and Indonesia.

The crash happened on Melville Island, about 40 miles north of Darwin, the Northern Territory's capital.

About 150 Marines are based in Darwin and up to 2,500 rotate through the city annually. They're part of a realignment of forces in the Asia-Pacific that's broadly meant to face an increasingly assertive China.

The Osprey is a hybrid aircraft that takes off and lands like a helicopter, but during flight can rotate its propellers forward and cruise much faster like an airplane. Versions of the aircraft are flown by the US Marine Corps, Navy and Air Force.

Before Sunday, there had been five fatal crashes of Marine Ospreys since 2012, causing a total of 16 deaths.

The latest was in June 2022, when five Marines died in a fiery crash in a remote part of California east of San Diego. A crash investigation report last month found that the tragedy was caused by a mechanical failure related to a clutch.

There had been 16 similar clutch problems with the Marine Ospreys in flight since 2012, the report found. But no problems have arisen since February when the Marine Corps began replacing a piece of equipment on the aircraft, the report said.