A search is underway Friday for 12 passengers on board two Marine Corps helicopters that collided mid-air off the coast of Hawaii, U.S. military officials told NBC News.
The helicopters were on a nighttime training mission when they crashed off the coast of Haleiwa, located on the North Shore of Oahu.
U.S. Coast Guard Petty Officer Sara Mooers told NBC affiliate KHNL the Marine Corps Air Station in Kaneohe requested assistance following a collision at 11:38 p.m. Thursday night.
"Crews discovered a life raft with no one on board and visible flames on the water," Mooers said.
The cause of the crash has not been determined.
Surf on Oahu’s North Shore is expected to be 30-40 feet high, beginning Friday, according to KHNL.