FAA, FBI and U.S. National Transportation Safety Board officials are investigating the crash of a Horizon Air Bombardier Q400 turboprop in woodland on Ketron Island near Tacoma, Washington, around 1.5 hr after it was stolen by an airline employee, believed to be a ground service agent.

The incident began around 8pm Pacific on Aug 10, when a Q400 made an unauthorized takeoff from Seattle’s SeaTac International airport. Although details remain scant at this time, operations at SeaTac were temporarily shut down and two Air National Guard F-15Cs, call sign Rock 41 and 42, from the 142nd Fighter Wing in Portland, Oregon, were scrambled to intercept the Q400. A U.S. Air Force KC-135R tanker was also dispatched from Fairchild AFB to support the F-15s.

Just after 10pm Pacific, Horizon parent company Alaska Airlines tweeted confirmation that “a Horizon Air Q400 that had an unauthorized takeoff from SeaTac around 8pm has gone down near Ketron Island in Pierce County, WA. We're working to confirm who was on board, we believe there were no guests or crew on board other than the person operating the plane.”

Pierce County Sheriff’s Department also tweeted that the suspect is “confirmed a suicidal male. Acted alone he is 29-year-old Pierce County resident. We are working background on him now.” Officials indicate the aircraft crashed due to pilot action and was not forced or shot down.

Washington State governor Jay Inslee later confirmed the events in a statement. “There are still a lot of unknowns surrounding tonight’s tragic incident of a stolen Horizon Air plane from SeaTac Airport. The responding fighter pilots flew alongside the aircraft and we were ready to do whatever was needed to protect us, but in the end, the man flying the stolen plane crashed on Ketron Island.”

The aircraft, registered N449QX, was delivered to Horizon in June 2012, and, according to the flight tracking website Flightradar24.com, had earlier that day operated scheduled flights to and from Victoria, on Canada’s Vancouver Island.  Prior to crashing, the aircraft was filmed conducting extreme maneuvers over the Puget Sound, including a barrel roll and inverted vertical dive culminating in a high g pull-out just a few feet above the water’s surface.