TORONTO, Ont. – Toronto Hydro said 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.

Several other smaller pockets in the downtown core were also without power.

The utility said that outage was caused by a fire in a circuit breaker and that all power had been 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.