OLYMPIA, Wash. (AP) -- Investigators worked to find out how a "suicidal" airline employee stole an empty Horizon Air turboprop plane, took off from Sea-Tac International Airport and crashed into a small island in the Puget Sound after being chased by military jets that were quickly scrambled to intercept the aircraft.
The Friday night crash happened because the 29-year-old man was "doing stunts in air or lack of flying skills," the Pierce County Sheriff's Department said. The man, who was believed killed, wasn't immediately identified.
The man was suicidal, and there was no connection to terrorism, Ed Troyer, a spokesman for the sheriff's department, said on Twitter.
Video showed the Horizon Air Q400 doing large loops and other dangerous maneuvers 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 takeoff and gate approach and de-ice planes.
The plane was pursued by military aircraft before it crashed on Ketron Island, southwest of Tacoma, Washington. Troyer said F-15 aircraft took off 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.
The aircraft was stolen 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. 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 airplane.
"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.
White House Press Secretary Sarah Huckabee Sanders said Saturday morning that President Donald Trump is "monitoring the situation." He's currently at his New Jersey golf club.
The U.S. Coast Guard sent a 45-foot (14-meter) vessel to the crash scene. Video showed fiery flames amidst trees on the island, which is sparsely populated and only accessible by ferry.
No structures on the ground were damaged, Alaska Airlines said.
Alaska Air Group CEO Brad Tilden said in a statement early Saturday morning that the airline was "working to find out everything we possibly can about what happened."
The airline was coordinating with the Federal Aviation Administration, the FBI and the National Transportation Safety Board, he said.
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."
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 responding fighter pilots flew alongside the aircraft and were ready to do whatever was needed to protect us, but in the end the man flying the stolen plane crashed," Inslee said.