The Marines were assigned to Marine Heavy Helicopter Squadron 465 of the 3rd Marine Aircraft Wing's Aircraft Group 16 at the Marine air station in Miramar, near San Diego. Capt. Morgan Frazer, a spokeswoman for the 3rd Marine Aircraft Wing, identified them as:
Capt. Samuel A. Schultz, 28, of Huntington Valley, Pennsylvania, a pilot who joined the service in May 2012.
First Lt. Samuel D. Phillips, 27, of Pinehurst, North Carolina, a pilot who joined the service in August 2013.
Gunnery Sgt. Richard Holley, 33, of Dayton, Ohio, a CH-53 crew chief who joined the service in November 2003. Holley was deployed to Iraq twice in support of the U.S.-led invasion, the Marine Corps said.
Lance Cpl. Joseph Conrad, 24, of Baton Rouge, Louisiana, a CH-53 crew chief who joined the service in May 2016.
"The hardest part of being a Marine is the tragic loss of life of a fellow brother-in-arms," said Col. Craig Leflore, the aircraft group's commanding officer.
The CH-53E is the largest and heaviest helicopter in the U.S. military. The aircraft that crashed Tuesday took off from the Marine Corps base in Twentynine Palms, California, and went down about 15 miles west of El Centro, the Marine Corps said. The cause remains under investigation.