About 550 Torontonians were without power this morning after an outage in the city's north end – the second in as many days.
Power was fully restored to about 1,100 residents living between Steeles and Finch Avenues West between Jane Street and Dufferin Avenue, a spokeswoman said.
While a cause of the 4 a.m. outage has yet to be determined, Toronto Hydro's Tanya Bruckmueller said equipment may be prone to over-heating when it is very hot outside.
"Over the next few days we may see more of our equipment over-heating, we're just starting to see it," she said.
Tuesday morning's outage follows a fire at a Kipling transformer on Monday afternoon that left about 250,000 people in the dark.
"There were people stuck in office towers…people who had to walk down 50 flights of stairs only to go out on the street and find traffic chaos on the streets because the traffic lights were out," CTV's John Vennavally-Rao told Canada AM Tuesday morning.
"Some of the subway system was shut down so it was just a miserable time for some people trying to get home last night.
"For the Queen, who was here for the official state dinner at the Fairmont Royal York, they lost power right up until the point when the dinner was supposed to start. They were on emergency back-up power and still they were able to pull off the whole event," he said.
While Toronto Mayor David Miller pleaded via Twitter for Torontonians to turn down their air conditioners, some experts note that there was still excess electricity available to the grid so consumption may not have been the cause.
A report by CTV's Paul Bliss points to last summer's recession as one reason there is a surplus of energy currently available to Ontarians.
"Power demand dropped 6 per cent last year in Ontario as large factories shut down. That's left us with us with a comfortable surplus of supply unlike years past when we were asked to cut back to avoid brown outs," he said.
"We're burning a lot of coal to meet the demand for your ac this week. In fact, coal is the second largest supplier of electricity today after nuclear."
By about 7:30 p.m. Monday, 47,000 consumers remained without power.
The fire at the 800 Kipling Ave. transformer site had been fully extinguished some time around 6 p.m.
That site is known as the Manby station, shared by Hydro One and Toronto Hydro. It houses a 230-kilovolt line that feeds electricity into downtown Toronto via the Runnymede and John Street transformer stations, reported CTV Toronto's Paul Bliss.
Gauvin said the cause of the fire is still being investigated.
"It's too soon to say. There are so many things that can contribute to a fire in electrical equipment, from lightning on to many other causes," she said.
