The Alaska Airlines plane that was stolen by an airline employee from Seattle-Tacoma International airport has crashed in Washington’s South Puget Sound.

No passengers were onboard during the incident and normal operations have resumed at the airfield, the airport said on Twitter.

The US fighter jets chased the planes to divert the Horizon Air Q400 from the crowded area after the airline employee conducted an unauthorized takeoff without passengers.

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

The Pierce County Sheriff’s Office said on Twitter that preliminary information suggested that a mechanic had stolen the aircraft. The tweet said the crash may have been caused by the mechanic ‘doing stunts in air or lack of flying skills.’

“This is not a terrorist incident. Confirmed info .. this is a single suicide male. We know who he is. No others involved,” Sheriff’s Office said.

“Male is confirmed a suicidal male. Acted alone he is 29-year-old Pierce county residence. We are working background on him now,” the sheriff’s department tweeted.