US investigators found on Sunday the Horizon Air passenger plane stolen by a troubled Seattle airport worker smashed to pieces on a sparsely populated island as his family reacted with "complete shock," CNN reported.
After falling through several 100-foot (30-metre) lines of trees, the Bombardier Q400 plane broke up into pieces small enough to pick up by hand, National Transportation Safety Board (NTSB) Western Pacific Region chief Debra Eckrote said.
"You couldn't even tell it was a plane except for some of the bigger sections, like the wing section," Eckrote said. "Even the small sections, most of it doesn't resemble a plane."
Two F-15 fighter jets chased the twin-engine turboprop plane that Richard Russell had hijacked.
During the hour he spent in the air, Russell flew the plane in a loop -- an improbable stunt caught on video by a surprised bystander -- then slammed it into Ketron Island in Puget Sound.
Authorities ruled out any link to terror, and determined Russell had flown alone. No one besides Russell was hurt, and the F-15s did not shoot down the plane, according to officials.
The local sheriff described Russell, nicknamed "Beebo," as "suicidal" when he flew off in an empty passenger plane from Seattle's main airport late on Friday. Colleagues remembered him as "quiet" and "very friendly."
NTSB investigators are set to analyse the recovered flight data recorder for clues next week.
Russell's family said the incident came as a "complete shock to us."
"It may seem difficult for those watching at home to believe, but Beebo was a warm, compassionate man," the family said in a statement.
We are "stunned and heartbroken" by the incident, the family said.
"He was a faithful husband, a loving son and a good friend."
Russell's role at Horizon, an Alaska Airlines affiliate where he had worked since 2015, involved towing aircraft, loading and unloading cargo and luggage, and cleaning the aircraft, officials said.