Yellowknife's firefighters were confronted by an unusual call on Monday evening as residents reported a fire at the city's swimming pool.
Witnesses said the fire began inside the pool's women's changing facility during a session of the city's Polar Bear Swim Club.
One parent in attendance described "proper black smoke billowing out of the change room" in a message to Cabin Radio. They said firefighters required the use of air vents to clear smoke from the scene.
Firefighters carried belongings out to swimmers once the fire had been dealt with.
On Tuesday, City spokesperson Kerry Penney said a dispenser inside the changing room had been set on fire, an incident she said was "deemed suspicious." RCMP were called and interviewed a number of people who had been in the facility at the time.
City councillor Niels Konge, who was at the pool, said firefighters handled the call "amazingly well."
There is no suggestion the pool itself or its occupants were directly threatened by the fire, and there are no reports of injuries at the time of publication.
The Ruth Inch Memorial Pool is open as usual on Tuesday with its regular schedule going ahead.