A “suicidal” airline employee stole an empty plane, took off from Seattle’s Sea-Tac International Airport and was chased by military jets before crashing into a small island, officials said.
Preliminary information suggests the crash occurred because the 29-year-old man was “doing stunts in the air or lack of flying skills”, the Pierce County Sheriff’s Department said.
Ed Troyer, a spokesman for the sheriff’s department, said on Twitter the man was suicidal and there was no connection to terrorism.
Video showed the Horizon Air Q400 doing large loops and other dangerous stunts as the sun set on the Puget Sound.
There were no passengers aboard. Authorities initially said the man was a mechanic, but Alaska Airlines later said he was believed to be a ground service agent employed by Horizon.
Those employees direct aircraft for take-off and gate approach and de-ice planes.
Witnesses reported seeing the plane being chased by military aircraft before it crashed on Ketron Island, south west of Tacoma, Washington.
Mr Troyer said F-15 aircraft scrambled out of Portland, Oregon, and were in the air “within a few minutes” and the pilots kept “people on the ground safe”.
The sheriff’s department said they were working to conduct a background investigation on the Pierce County resident, whose name was not immediately released.
The aircraft was stolen at about 8pm, Alaska Airlines said it was in a “maintenance position” and not scheduled for a passenger flight.
Horizon Air is part of Alaska Air Group and flies shorter routes throughout the US West. The Q400 is a turboprop aircraft with 76 seats.
Pierce County Sheriff Paul Pastor said the man “did something foolish and may well have paid with his life”.
The man could be heard on audio recordings telling air traffic controllers that he is “just a broken guy”.
An air traffic controller called the man “Rich”, and tried to convince the man to land the plane.
“There is a runway just off to your right side in about a mile,” the controller says, referring to an airfield at Joint Base Lewis-McChord.
“Oh man. Those guys will rough me up if I try and land there,” the man responded, later adding “This is probably jail time for life, huh?”
Later the man said: “I’ve got a lot of people that care about me. It’s going to disappoint them to hear that I did this…Just a broken guy, got a few screws loose, I guess.”
Flights out of Sea-Tac, the largest commercial airport in the Pacific Northwest, were temporarily grounded during the drama.