There was minor damage after a fire Friday evening on the roof of Market Square.
Platoon Chief Brian Wilson of the Saint John Fire Department said firefighters found smoke in the building when they arrived.
Wilson said they discovered the smoke was being pumped in through the HVAC system on the roof, where they found a small fire had begun in some roofing material.
Three crews doused the flames while another crew protected some assets in the library area, he said.
Wilson said firefighters were on scene for about two hours and no one was hurt.