SEATAC, Wash. - An airline employee stole an empty Horizon Air turboprop plane at Seattle-Tacoma International Airport (Sea-Tac), took off unauthorized and then crashed late Friday, officials said. The Pierce County Sheriff's Office said the man was 29 and "suicidal."

Ed Troyer, a spokesman for the Pierce County Sheriff's Department, said on Twitter that preliminary information suggests the crash occurred because the man was "doing stunts in air or lack of flying skills."

There was no connection to terrorism and no others were involved, said Troyer.

The aircraft was stolen at about 8 p.m. 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 U.S. West.

Pierce County Sheriff Paul Pastor said the man "did something foolish and may well have paid with his life." 

Video showed the Horizon Air Q400 doing large loops and other dangerous maneuvers as the sun set on the Puget Sound. The Q400 is a turboprop aircraft with 76 seats. There were no passengers aboard.  

The man could be heard on audio recordings telling air traffic controllers that he is "just a broken guy." An air traffic controller called him "Rich," and tried to convince him to land the airplane. 

"There is a runway just off to your right side in about a mile," the controller says, reffering 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?" 

"I've got a lot of people that care about me," the man later said. "It's going to disappoint them to hear that I did this...Just a broken guy, got a few screws loose, I guess." 

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 takeoff and gate approach and de-ice planes.   

Witnesses reported seeing the plane being chased by military aircraft before it crashed on Ketron Island, a small island in the Puget Sound that is home to about two dozen residents. Troyer said two F-15 military planes scrambled out of Portland, Oregon, and were in the air "within a few minutes" and the pilots kept "people on the ground safe." He said the military planes were not involved in the crash. 

Royal King told The Seattle Times he was photographing a wedding when he saw the low-flying turboprop being chased by two F-15s. He said he didn't see the crash but saw smoke. 

"It was unfathomable, it was something out of a movie," he told the newspaper. "The smoke lingered. You could still hear the F-15s, which were flying low."

The U.S. Coast Guard sent a 45-foot vessel to the crash scene after witnesses reported seeing a large plume of smoke in the air, Petty Officer Ali Flockerzi said. Video showed fiery flames amidst trees on the island, which is sparsely populated and only accessible by ferry. 

Alaska Airlines said no structures on the ground were damaged. 

Flights out of Sea-Tac, the largest commercial airport in the Pacific Northwest, were temporarily grounded during the drama. The airport said that normal operations have since resumed.

"Our hearts are with the family of the individual aboard, along with all of our Alaska Air and Horizon Air employees," Horizon Air Chief Operating Officer Constance von Muehlen said in a video posted on Twitter.    

Gov. Jay Inslee thanked the Air National Guard from Washington and Oregon for scrambling jets and said in a statement "there are still a lot of unknowns surrounding tonight's tragic incident."

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 FBI said it was "communicating with local, state, and federal partners but it is too early for us to put out details on the rapidly evolving situation."    

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