A sauna at Le Nordik Spa in Chelsea, Que., was completely destroyed by fire on Friday night.
It started at about 6 p.m. An employee spotted something wrong in the fireplace during a routine inspection and called firefighters.
No one else was in the Maa sauna at the time, and no one was injured.
The damage is estimated at about $250,000.
Activities at the spa were disrupted, but the rest of the spa remained open. An evacuation wasn't necessary, police said.
The cause of the fire is still under investigation, but it's not believed to be criminal.
The spa opened for business as usual Saturday.