Authorities say a Riverdale building was evacuated Monday after an electrical fire.

Emergency officials say at least five people were treated for minor injuries when 255 Fieldston Terrace was evacuated due to high carbon monoxide levels. Assistant Fire Chief James Esposito says a city contractor working on sewers accidentally pulled on low-voltage power lines going into the building, which sparked the fire.

All of the building's tenants were allowed to return home after about three hours, authorities say.