WAIMANALO, Hawaii, May 18 (UPI) -- A U.S. Marine was killed and 21 others were hospitalized when a military aircraft went down at Bellows Air Force Base in Hawaii on Sunday.
Marine Corps officials said the MV-22 Osprey aircraft experienced a "hard-landing mishap" during a routine training exercise.
The Marines on board the aircraft were members of the 15th Marine Expeditionary Unit, which left San Diego last week on a seven-month deployment to the Pacific Command and Central Command.
Marine Corps spokesman Capt. Alex Lim told Hawaii News Now that the cause of the crash is still under investigation.
"It's tragic and our condolences go out to the families and the loved ones of the victim. But right now we need to investigate further and see what happened," Lim said.
Photos and video posted to social media show a black cloud of smoke coming from the crash site.
Officials have yet to identify the Marine who was killed.