Officials with the Transportation Safety Board of Canada (TSB) say the complex investigation into Thursday night’s plane crash that claimed the lives of four people, including former Alberta premier Jim Prentice, is underway and is expected to last for up to a year.

Investigators have confirmed the Cessna Citation departed Kelowna Thursday night and was destined for the Springbank Airport outside Calgary. The aircraft struck terrain at a location approximately 11 kilometres north of the Kelowna Airport and the four occupants of the pain suffered fatal injuries.

The pilot of the aircraft, identified by family as Jim Kruk, did not make any emergency or distress calls and the plane's emergency locator transmitter signal was not received.

The TSB says the aircraft was not equipped with a cockpit voice recorder (CVR) or a flight data recorder (FDR), equipment not required in the plane.

At this time, five TSB investigators have been assigned to the crash scene and evidence is being collected.