Aircraft crashes after 'stolen' plane takes off from Seattle Tacoma International Airport

This story has been updated. Find the most recent version here.

A plane has crashed in south Puget Sound after an airline employee stole a plane andtook off from Seattle Tacoma International Airport on Friday night, police said.

No passengers were on board andaccording to thePierce County Sheriff's Department, this is not a terrorist incident.

The department said the employee was a 29-year-old man, whose identity has been confirmed.

The Pierce County Sheriff's Department said twoF-15military jets chased the plane, but were not involved in the crash.

"There is no indication that the person flying this plane was trying to damage anything or attack anything," saidSherriff Paul Pastor of Pierce County in a press conference.

Crashed into island

"Most terrorists don't do loops over the water. This might have been a joyride gone terribly wrong."

Pastor said the plane crashed intoKetronIsland, a small heavily wooded island with about 20 full-time residents. He said fire units are on their way to the island to put out a small fire caused by the crash.

According to a tweet from Alaska Airlines, the plane is a Horizon AirQ400.

All planes leaving Seattle Tacoma International Airport were temporarily grounded but according to a tweet from the airport, normal airport operations have resumed.

'Way too low'

Irvington Billingsworth said he wasat Chambers Bay Golf Course, which is southwest of Tacoma, when suddenly he saw a plane flying very low overhead.

"We were like whoa, that plane's so low. So I'm like maybe it just left the airport. But then I was like whoa, that's way too low," he said.

Billingsworth said he saw what appeared to be two jets following the plane.

He said he heard a loud "boom," then saw smoke coming from a spot in Puget Sound where the plane appeared to have crashed.

Four flights departing from Seattle to Vancouver were delayed because of the grounding. One flight from Toronto to Seattle is being diverted to Vancouver asSeaTacairport recovers from the temporary closure.

Read more from CBC British Columbia