Authorities are working to recover the wreckage of a plane crash in western Alaska that killed 10 people while investigators are trying to determine what caused the small commuter aircraft to go down in the icy Bering Sea.

Officials are still investigating what caused a small commuter plane to crash out of the sky over Alaska last week, killing all 10 people aboard — but Joel Natwick, a longtime pilot in the state, thinks ice could be to blame.

The aircraft operated by Bering Air dropped off the radar on Thursday afternoon. The bodies of all 10 onboard were recovered Saturday.