Seven Marines were killed in a collision of two helicopters, one of them similar to this one, near Yuma, Ariz., during night training exercises Wednesday. 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 involved an AH-1W "Cobra" and UH-1 "Huey" helicopter.