An airline employee stole an Alaska Airlines Q400 passenger airplane from Seattle–Tacoma International Airport (Sea-Tac) late Friday night and has since crashed on Ketron Island in the southern Puget Sound. No passengers are believed to have been on board the plane. According to local media, witnesses reported seeing F-15 fighter jets chasing the plane, followed by smoke and loud boom.

What we know
Sea-Tac airport confirmed on Twitter at 12:31 am EDT that “An airline employee conducted an unauthorized takeoff without passengers at Sea-Tac; aircraft has crashed in south Puget Sound.”
The Pierce County Sheriff’s Department told NBC News that the airline employee who stole the plane was “a single suicide male,” that there were no passengers on the plane, and that “this is not a terrorist incident.”
The Sheriff’s Department also tweeted: “Preliminary info is that a mechanic from unknown airlines stole plane. Was doing stunts in air or lack of flying skills caused crash into Island.”
A spokesperson for the Federal Aviation Administration (FAA) confirmed to NBC News that a “security issue” involving SeaTac airport in the Seattle area is being investigated.
At 12:16 am EDT, Alaska Airlines tweeted: “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.”
Aviation journalist Jon Ostrower was able to capture audio of the final radio call between the pilot, who called himself “Rick,” and air traffic controllers on the ground.
What we don’t know
Whether the plane crashed on its own or was shot down
The name of the person who stole the plane and why they did it
If the person who stole the plane survived the crash
This is a developing news story. This post will be updated as more information comes in.

An Airline Employee Stole A Plane From Seattle Airport And Was Chased By Fighter Jets Before Crashing https://www.buzzfeednews.com/article/passantino/plane-stolen-seattle-airport-crash
Full details on here!

Recorded conversation between the air traffic controller and the alleged hijacker
http://garchives1.broadcastify.com/15227/20180810/201808102255-590200-15227.mp3