A passenger on a charter flight in northern Canada forced open the aircraft's door and leapt to his death, making the freezing cabin depressurise at 23,000 feet.
Royal Canadian Mounted Police Staff Sgt Harold Trupish said the incident happened during a flight to Cambridge Bay, a community in western Nunavut.
The Adlair Aviation King Air 200 twin-engined turboprop was about 110 miles from the Cambridge Bay airport when the man jumped.
Staff Sgt Trupish said the pilots reported that the 20-year-old passenger had become unruly and that they were unable to prevent him from jumping.
Police are searching for the body of the man, who was not named.
Paul Laserich, the airline's general manager said the opened door caused the cabin to depressurise, filling the cockpit with a roar of frigid, Arctic air. He praised the pilot for his quick-thinking decision to land the aircraft.
"They brought the ship safely back. Everybody is OK. They are a little shaken up. They are OK. That is what is most important," said Mr Laserich
The pilot was said to be too distressed to talk to reporters.