Plane Crashes After Being Stolen From Seattle Airport

The pilot attempted aerial stunts before crashing.

A plane has crashed after an airline employee took off without permission from a Seattle airport, attempted stunts in the air, and was pursued by fighter jets.

Plane Crashes After Being Stolen From Seattle Airport

Alaska Airlines confirmed an "unauthorised takeoff" of a Horizon Air Q400, a twin-propeller passenger plane, from Sea-Tac airport on Saturday afternoon (AEST). The airline said the plane "was taken from a maintenance position and was not scheduled for passenger flight".

Witnesses reported a plane being flown low over Seattle. Audio of the pilot -- said to be an employee of Alaska, who identified himself as 'Rick' --  speaking on radio to the SeaTac air traffic control is being shared on social media, with the man saying he was not confident he could land the plane.

Witnesses reported seeing fighter jets intercept the plane, then the Q400 crashing soon after into the Puget Sound, a body of water leading to the ocean just off Seattle.

Washington state governor Jay Inslee confirmed fighter planes were called in, and said the Alaska plane was "stolen".

A local police department said the man had been attempting "stunts" in the air. Police also said the incident was not related to terrorism.

SeaTac confirmed the plane crashed after being piloted by an employee.

Flights from the airport were grounded as authorities dealt with the situation.