Stolen plane from Seattle airport crashes in the Puget Sound

A turboprop passenger plane stolen from Seattletacoma International Airport crashed Friday night on Ketron Island, off the shore from Steilacoom, authorities said.

Only the unknown pilot was on the plane, according to authorities.

Pierce County sheriff’s spokesman Ed Troyer said the man who stole the plane is a mechanic at the airport. He described him as a white man, age 29, who might have mental health problems. He is reported to be a Pierce County resident.

“The guy didn’t know how to fly or intentionally did stunts over Anderson Island, and crashed into Ketron Island,” Troyer said.

Alaska Airlines, the parent company of Horizon Air whose plane was stolen, tweeted a statement about 9:15 p.m.

“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.”

Fire crews and boats responded to the scene. Based on video from KIRO 7, the crash started a forest fire on the island.

“We have multiple 911 calls, over 30, reporting a fireball,” Troyer said. “Witnesses said a ... plane is going down. We have police boats, we have everybody responding. We’re trying to contact the military. We are sending resources and people.”

Two F-15 fighters were scrambled from the Portland airport and followed the plane as it flew over the region, the Federal Aviation Administration reported.

The incident shut down Sea-tac Airport, but normal operations resumed around 9:30 p.m.

The FBI is involved in the investigation, Troyer said.