Toronto Hydro says all 6,500 downtown customers left in the dark by an outage now have their electricity restored.
The blackout hit at about 8:15 p.m. Thursday in an area roughly bordered by Jarvis St. and the Don Valley Parkway and from Carleton St. to Queen's Quay.
The utility says that the outage was caused by a fire in a circuit breaker and that all power was restored by just after 4 a.m.
The blackout left homes and businesses without air conditioning after a day in which the city had posted an extreme heat alert for the second day in a row.