TORONTO – A six-storey apartment building in North York was evacuated as emergency crews determine the source of a natural gas leak, Thursday.

Firefighters were called to building, located at 801 Sheppard Ave. W., near Wilson Heights Boulevard, at around 4:30 a.m.

Police told 680News high levels of a gas, likely carbon monoxide, were detected.

No injuries have been reported.

Residents from the apartment are keeping warm in supplied TTC buses.