A high-rise condo building in uptown Waterloo was evacuated Wednesday due to a carbon monoxide leak.

Firefighters were called to the building at 144 Park Street around noon. When they arrived, their equipment alerted them to high carbon monoxide levels in the building.

The leak was traced to an issue with a rooftop heating unit. According to Waterloo Fire Rescue, the leak was shut down and the building ventilated to remove all traces of the potentially deadly gas.

One resident of the building took themselves to hospital for treatment. No other injuries were reported.

Everyone was allowed back inside by mid-afternoon.