MISSOULA, Mont. -

A twin-engine plane crashed at Lost Trail Ski Area Tuesday evening near the Montana-Idaho state line.

Federal Aviation Administration spokesman Allen Kenitzer says preliminary information indicates the plane was a Grumman G-21A with only the pilot on board.

Ravalli County Sheriff Chris Hoffman said the plane is larger than initially thought -- it is a twin-engine plane.

Officials have not yet determined who owned the plane, where it was coming from or who was on board.

People attending a meeting at Lost Trail Ski Area said they heard a massive crash at about 5:30 p.m. and ran to see what happened.

One witness said the plane dropped hard and flat, right out of the sky. Witnesses also said it looked like flames immediately engulfed the plane.

Lost Trail straddles the Montana and Idaho state line. It's about 95 miles south of Missoula.

National Transportation Safety Board and FAA officials will investigate Wednesday.

Below is a press release from the Ravalli County Sheriff's Office:

Ravalli County Undersheriff and Chief Deputy Coroner Steve Holton said that investigators have tentatively identified the aircraft and pilot involved in the airplane crash at Lost Trail Ski Area yesterday evening. At this time, the pilot is believed to have been the only occupant of the aircraft. The pilot’s name is being withheld pending confirmation of the identification and notification of the family. The FAA is investigating the circumstances of the crash. Media requests can be made to the NTSB Media Source at (202) 314-6290.