Crews in Alaska are searching for a plane that went missing with 10 people on board while over Norton Sound off Nome.

The Cessna Caravan left Unalakleet at 2:37 p.m., and officials lost contact with it less than an hour later, according to David Olson, director of operations for Bering Air. The aircraft was 12 miles offshore, the U.S. Coast Guard said. It was operating at its maximum passenger capacity, according to the airline’s description of the plane.