The theft of an empty plane from Sea-Tac Airport highlights one of the biggest potential perils for commercial air travel - airline or airport employees causing mayhem

• Richard Russell, an airline ground agent at Sea-Tac International Airport, stole an empty Horizon Air turboprop plane and fatally crashed into a small island on Friday night.
• Officials said Saturday that the 29-year-old was a 3.5-year Horizon employee and had clearance to be among aircraft, but that to their knowledge, he wasn't a licensed pilot.
• At a news conference on Saturday, officials from Alaska Airlines and Horizon Air said they are working with authorities to investigate what happened.
• The incident highlights one of the biggest potential perils for commercial air travel: airline or airport employees causing mayhem.

The theft of an empty turboprop plane by an airline worker at Sea-Tac International Airport who performed dangerous loops before crashing into a remote island in Puget Sound illustrated what aviation experts have long known: One of the biggest potential perils for commercial air travel is airline or airport employees causing mayhem.

Investigators are piecing together how the airline ground agent working his regular shift stole an empty Horizon Air turboprop plane, took off Friday night from Sea-Tac and fatally crashed into the a small island after being chased by military jets that were quickly scrambled.

Officials said Saturday that the man, identified as 29-year-old Richard Russel, was a 3.5-year Horizon employee and had clearance to be among aircraft, but that to their knowledge, he wasn't a licensed pilot.

Russell is presumed dead after crashing the plane into a small island.

Video of the incident shows the Horizon Air Q400 Russell stole doing large loops and other dangerous maneuvers.

Two F-15C aircraft pursued the plane but didn't fire at it before it cashed on Ketron Island, southwest of Tacoma.

No structures were damaged in the crash, though it did spark a small wildfire.

Russell could be heard on audio recordings telling air traffic controllers that he is "just a broken guy."

At a news conference on Saturday, officials from Alaska Airlines and Horizon Air said they are working with authorities to investigate what happened.

"Last night's event is going to push us to learn what we can from this tragedy so that we can ensure this does not happen again at Alaska Air Group or at any other airline," said Brad Tilden, CEO of Alaska Airlines.

The incident points to a large potential danger for commercial air air travel: airport employees causing mayhem.

"The greatest threat we have to aviation is the insider threat," Erroll Southers, a former FBI agent and transportation security expert, told the AP. "Here we have an employee who was vetted to the level to have access to the aircraft and had a skill set proficient enough to take off with that plane."

Ground service agents direct aircraft for takeoff and gate approach and de-ice planes, as well as handle baggage.

There was no connection to terrorism, said Ed Troyer, a spokesman for the sheriff's department.