An airline employee crashed a commercial passenger plane Friday evening after conducting an unauthorized takeoff at Sea-Tac, according to Sea-Tac International Airport. 

Alaska Airlines CEO Brad Tilden confirmed Saturday morning that the person who stole the Horizon Air plane died in the crash.

The FBI was leading an investigation into the incident, Tilden said.

Sea-Tac Airport officials initially said Friday night that an airline employee conducted an unauthorized takeoff without passengers at Sea-Tac, and that the plane has crashed in Puget Sound. 

Alaska Airlines tweeted "We've confirmed 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." 

Local law enforcement, the Pierce County Sheriff's Office, said on Twitter that the plane crashed on Ketron Island in the Puget Sound. "Preliminary info is that a mechanic from an unknown airlines stole plane. Was doing stunts in air or lack of flying skills caused crash into Island."

CBS News reports Ketron Island is a small island with about two dozen residents. 

"Two military F 15 chased plane but was not involved in crash," the Sheriff's Office tweeted. 

The Sheriff's Office also said the incident is not terror-related, but rather a single suicidal 29-year-old male from Pierce County. 

The man could be heard on audio recordings telling air traffic controllers that he's "got a lot of people that care about me" and that he is "just a broken guy."

The Horizon Air Chief Operating Officer posted a brief statement to YouTube late Friday night.

Twitter lit up Friday evening with photos and videos from those in the area, showing the incident and its aftermath, including an apparent fighter jet response. 

Normal operations have resumed at the airport, according to Sea-Tac's official Twitter account. 

Copyright 2018 KTVA. All rights reserved. The Associated Press contributed to this report.