7 U.S. Marines were killed Wednesday night during a training exercise in Arizona when 2 helicopters collided, NBC News reports.
The names of the Marines have not been released.
More from the AP:
Seven Marines were killed in a collision of two helicopters near Yuma, Ariz., during night training exercises, the Marine Corps said Thursday.
Lt. Maureen Dooley with Miramar Air Base in California said the service members with the 3rd Marine Aircraft Wing were based at Camp Pendleton north of San Diego. The crash around 8 p.m. Wednesday involved an AH-1W "Cobra" and UH-1 "Huey" helicopter, she said.
The aircraft collided in a remote portion of the Yuma Training Range Complex.
"We're still gathering a lot of details as the sun comes up," Dooley said.
It will be at least 24 hours before the Marine Corps releases the names of those killed, she said.
Capt. Staci Reidinger, director of public affairs at Marine Corps Air Station Yuma said earlier Thursday that the crash happened west of the Chocolate Mountains in California, though the exact location hasn't been confirmed.
"It's not in a populated area," she said.
Cpl. Steven Posy with Marine Corps Air Station Miramar said Thursday the weather "was pretty mild last night."
Several accidents have happened in the past year involving Marine Corps training in Southern California.
In September, a helicopter went down during a training exercise at Camp Pendleton, killed the two Marines onboard and set off a fast-moving brush fire at Camp Pendleton.
In August, two Marines were ejected from their F/A-18 Hornet fighter jet as it plunged toward the Pacific Ocean. The two Marines spent four hours in the dark, chilly ocean before they were rescued. Both suffered broken bones but survived.
In July, a decorated Marine from western New York was killed during a training exercise when his UH-1Y helicopter went down in a remote section of Camp Pendleton, north of San Diego.
Another Hornet sustained at least $1 million damage when its engine caught fire on March 30 aboard the USS John C. Stennis during a training exercise about 100 miles off the San Diego coast. Eight sailors, a Marine and two civilians were injured.
A decade ago, in February 2002, a helicopter crash in the Chocolate Mountains in eastern Imperial County, Calif., killed two Camp Pendleton Marines and injured two others. The UH-1N Huey was on a routine training mission in the Naval gunnery range.
The Cobra carries a crew of two, a pilot and gunner, and is considered the Marine Corps' main attack helicopter. The UH-1Y, which is replacing the aging version of the Huey utility helicopter first used during the Vietnam War, carries a crew of one or two pilots, a crew chief and other crew members, depending on the mission.