Seven Marines were killed during night training west of Yuma, Ariz., Wednesday when two helicopters collided, the Marine Corps told ABC News.
Six of the Marines were from Camp Pendleton and one was from Marine Corps Air Station Yuma.
The crash occured around 8 p.m. and the helicopters, belonging to the 3rd Marine Aircraft Wing, were identified as a two seat Cobra attack helicopter and an UH-1 trooper carrier, commonly known as a Huey.
The names of those who died in the crash will not be released by the Marine Corps until their next of kin have been notified.
The helicopters went down along the California/Arizona border just outside of the Yuma Training Range Complex.
Yuma is an area used extensively for helicopter and fighter jet training because the desert landscape is similar to Afghanistan.
ABC News' Martha Raddatz and Luis Martinez contributed to this report.