Six of the Marines killed belonged to a Camp Pendleton - based squadron , the Corps says . ` Every single one of these Marines impacted our squadron in their own special way and the entire Marine Corps aviation community is feeling their tragic loss , '' said Lt. Col. Stephen Lightfoot , commanding officer of Marine Light Attack Helicopter Squadron 469 . One Marine was assigned to a Yuma - based squadron , the Corps says . The cause of the deaths remains under investigation , it says . The Marines were preparing to deploy to Afghanistan , the Corps says .
Six of the Marines killed belonged to a Camp Pendleton - based squadron , the Corps says . One Marine was assigned to a Yuma - based squadron , the Corps says . The cause of the deaths remains under investigation , it says . The Marines were preparing to deploy to Afghanistan , the Corps says .