Survivors sought after US military helicopters collide
Rescuers are searching for survivors after two US Marines helicopters carrying 12 crew members collided off the Hawaiian island of Oahu during a night-time training mission.
It is not yet known what caused the crash, or if any survivors have been found.
The transport helicopters were both carrying a crew of six from Marine Corps Base Hawaii, when they crashed.
The CH-53Es came from the 1st Marine Aircraft Wing, Marine Capt Timothy Irish said.
Known as Super Stallions, they are the US military's largest helicopter, capable of carrying a light armoured vehicle, 16 tonnes of cargo or a team of combat-equipped Marines, according to a Marine Corps website.
A Coast Guard helicopter and a C-130 aeroplane has already spotted debris offshore, officials said.
The search includes aircraft from the US Navy and Air Force, a Honolulu Fire Department rescue boat and Coast Guard cutters.
A swell approaching the area will bring dangerously high waves to beaches and seas of up to 20ft near the rescue operation, National Weather Service meteorologist Matthew Foster said.
Elaray Navarro, who lives across the street from the beach at Haleiwa, said she heard two "booms" that were loud enough to shake her house.
"I threw my blanket off, put my slippers on and ran outside thinking it was a car accident," she said.
"I pray to the man upstairs to help them. To bring them home safely."