Four U.S. Marines were killed when a military helicopter crashed near El Centro, California, officials confirmed Wednesday.
The U.S. Marine Corps said a CH-53E Super Stallion from the 3rd Marine Aircraft Wing at MCAS Miramar crashed just outside of El Centro near the U.S.-Mexico border on Tuesday at around 2:35 p.m.
Bodies of the crew members were recovered from the wreckage and moved to the coroner's office, where Marine officials will take custody of them.
The cause of the crash is under investigation.
"It was pretty much a warm clear day," said Chief Deputy Thomas Garcia with the Imperial Valley Sheriff's Office. "Nothing stormy or rainy or anything like that."
USMC officials said the helicopter had left Marine Corps Air Ground Combat Center Twentynine Palms to conduct routine training of aircraft landings in unimproved zones.
Officials said the Marines were from 3rd Marine Aircraft Wing but have not identified them.
The names of the crew members were expected to be released after their relatives were notified, said Capt. Morgan Frazer with the 3rd Marine Aircraft Wing.
She said the squadron involved in the crash and other details also should be released.
Tuesday's California crash is the deadliest involving a Marine aircraft since a KC130T transport plane went down in Mississippi last July, killing 15 Marines and a sailor.
The California crash also occurred on the same day that a Marine Harrier jet crashed during takeoff from an airport in the East African nation of Djibouti. The pilot managed to eject and was being medically evaluated, military officials said.
The CH-53E Super Stallion is the largest helicopter in the U.S. military. It is used for minesweeping and transport and can carry dozens of troops and tons of cargo.
Two years ago, 12 Marines died when two of the helicopters collided off the coast of Oahu in Hawaii.
Last October, a CH-53E helicopter crashed and burned in Okinawa but nobody was injured.
In 2005, 31 people died when a CH-53E helicopter went down in Iraq during a sandstorm.