Power has been restored to part of downtown Toronto Tuesday morning, Toronto Hydro says.
The outage had left thousands in the dark and some street corners without traffic lights.
The affected area was between Queen Street on the north and The Esplanade on the south, and Bay Street on the west and George Street on the east.
The problem involved from 6,000 to 8,000 customers.
Smaller other pockets of the city were also affected by the power outage, which occurred after a morning thunderstorm.
Toronto Hydro does not know the cause of the problem, spokeswoman Tanya Bruckmueller said in an e-mail.
Some traffic lights were not working but the subway system still operated.
Toronto Fire Services dealt with seven calls to free people stranded in elevators in the outage area.