SEATAC, Wash. — The FBI has taken over the investigation of the “suicidal” airline employee who stole an empty Horizon Air turboprop plane, took off from Sea-Tac International Airport and was chased by military jets before crashing into a small island in the Puget Sound on Friday night, officials said.

Preliminary information suggests the crash occurred because the 29-year-old man was “doing stunts in air or lack of flying skills,” the Pierce County Sheriff’s Department said.

Ed Troyer, a spokesman for the Pierce County Sheriff’s Department, said on Twitter the man was suicidal and there was no connection to terrorism.

The FBI in Seattle also says there does not appear to be a link to terrorism.

The FBI continues to work with our state, local, and federal partners to gather a complete picture of what transpired with tonight's unauthorized Horizon aircraft takeoff and crash. We don't anticipate that further details will be available tonight. — FBI Seattle (@FBISeattle) August 11, 2018

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.

Some dude stole a plane from #Seatac (Allegedly), did a loop-the-loop, ALMOST crashed into #ChambersBay, then crossed in front of our party, chased by fighter jets and subsequently crashed. Weird times. pic.twitter.com/Ra4LcIhwfU — bmbdgty (@drbmbdgty) August 11, 2018

Witnesses reported seeing the plane being chased by military aircraft before it crashed on Ketron Island, southwest of Tacoma, Washington. 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.”

Washington Governor Jay Inslee said the stolen plane was not shot down by the military aircraft but crashed on its own.

There are still a lot of unknowns surrounding tonight's tragic incident of a stolen Horizon Airline plane. 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. — Governor Jay Inslee (@GovInslee) August 11, 2018

The sheriff’s department said they were working to conduct a background investigation on the Pierce County resident, whose name was not immediately released.

Stuck on the taxiway at Seattle SeaTac Airport- getting reports a plane was stolen. No planes are moving. @ABC7 pic.twitter.com/BAl3aEELwb — Leslie Lopez (@abc7leslielopez) August 11, 2018

Halfway down the runway on Alaska airlines out of Seattle and the pilot slams on the brakes and shares we must go back to the gate. Quite a scary experience. Not entirely sure what’s happening. Someone sneak on board? — Ben Schaechter (@Bensign) August 11, 2018

Twitter lit up with posts speculating about the circumstances of the plane’s hijacking and what might happen.

Air traffic controllers We’re trying to get someone named “Rich” piloting the on authorized Horizon flight to land safely. We’re following reports of a crash now near Anderson Island — Gary Horcher (@GaryKIRO7) August 11, 2018

FAA sources say it appears an airline employee stole a Horizon Air Turbo Prop from SeaTac and took off and crashed Ketron Island outside Seattle https://t.co/cUoWB7ruJt — Kris Van Cleave (@krisvancleave) August 11, 2018

After a chase by fighter jets, the aircraft crashed.

Video showing the moments that the stolen plane crashed outside of Seattle pic.twitter.com/ZkHvhouHlN — Kris Hanson (@KrisHansonRCF) August 11, 2018

We are aware of an incident involving an unauthorized take-off of a Horizon Air Q400. We believe there are no passengers on board. More information as we learn more. — Alaska Airlines (@AlaskaAir) August 11, 2018

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, 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?”

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.

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.

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.”

“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.

Spokesmen for the Transportation Security Administration, the U.S. Department of Homeland Security and the Federal Aviation Administration directed inquiries to local authorities.

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.”

AP journalist Michelle A. Monroe in Phoenix contributed to this report