Two Marines were killed, but there was no information on whether they died at the scene or at the hospital. The two other crew members were injured.
Capt. Tanya Murnock of Marine Corps Air Station Yuma said this morning the surviving Marines did not have life-threatening injuries. The identities of the four Marines had not been released this morning.
Murnock said the crew had flown out of Marine Corps Air Station Miramar to train in the gunnery range.
She did not have information on what squadron the crew was assigned to and whether the crew was based at Miramar.
More information on the fatal crash, including the identities of the crew members, is expected to be released today.
Earlier this month, three Marines were killed and four others were injured at Camp Pendleton north of San Diego when a 5-ton truck rolled over during a night artillery exercise. The canvas-topped truck overturned during a Feb. 6 exercise in which an artillery unit was practicing firing and moving from one location to another.
Both training accidents follow the deaths of nine Southern California-based Marines in aviation crashes this year while supporting the war in Afghanistan.
The UH-1N Huey helicopter is a twin-piloted, twin-engine helicopter used in casualty evacuation and troop transport. The $4.7 million aircraft is considered to be the most widely used helicopter in the world, with more than 9,000 produced since the 1950s.
>> The Associated Press contributed information to this article.
>> Staff Writer Darren Simon can be reached at 337-4082.