WASHINGTON » The military has opened an investigation into Saturday’s devastating helicopter crash in eastern Afghanistan that killed 30 U.S. troops and eight Afghans.

Pentagon officials would not discuss the details of the probe, but it will no doubt address a host of questions surrounding the crash, including a look at the insurgent threat and the instructions given to the special operations team crowded into the Chinook helicopter as it raced to assist other U.S. forces.

According to officials, the team, which included 22 Navy SEAL personnel, three Air Force troops, a five-member Army aircrew and a military dog, was flying in to help U.S. Army Rangers who were going after insurgents on the ground. Seven Afghan commandos and an Afghan interpreter were also on board.

The helicopter apparently was shot down by an insurgent armed with a rocket-propelled grenade.

Gen. James Mattis, head of U.S. Central Command, has appointed Army Brig. Gen. Jeffrey Colt to lead the investigation.