The cause of the crash remains under investigation , said 1st Six of the Marines killed belonged to a Camp Pendleton-based squadron , the Corps says . The other three were from Marine Medium Helicopter Squadron 463 out of Twentynine Palms, The cause of the accident remains under investigation , Marines 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 . The other three were from Marine Medium Helicopter Squadron 463 out of Twentynine Palms, The cause of the accident remains under investigation , Marines says . The Marines were preparing to deploy to Afghanistan , the Corps says .