The Transportation Safety Board sent investigators to Calgary International Airport on Thursday after a WestJet passenger plane was forced to return after taking off.
The board said there was a fire in the cargo compartment of the Boeing 737.
WestJet said in a statement that shortly after takeoff the crew on Flight 113 from Calgary to Vancouver was alerted by a fire indication light.
The statement said all passengers and crew were safe and were unloaded after landing.
WestJet apologized for the delay and inconvenience, but said safety is its first priority.
The plane has been removed from service for further inspection.