Hydro Quebec says the power failures which have hit the Montreal urban area this week were exceptional events -- but could very well happen again.

The outages began when three electricity relay stations in remote parts of the province were disabled by intense blazes, leaving up to 500,000 without electricity on Thursday.

In the late afternoon Hydro Quebec announced that all three stations had been repaired and only 300,000 were without power. One hour later that total had been whittled down to 37,000 and by eight p.m. all was reported to be back to normal. 

The outages mainly hit the Montreal area, the Laurentians, Monteregie and Lanaudiere regions.

Hydro Quebec’s chief blamed the problem on smoke.

“The smoke from the forest fires coming onto the lines ionizes the air and as that happens, automatic relay protections trigger and when that happens major transmission line from up north went off-line and that had a cascading effect on another number of lines,” said Hydro Quebec President Thierry Vandal.

Gary Sutherland said utility was doing what it could.

"We're trying to redirect as much power as we can to the other axis further east," said Sutherland. "It's like a big giant with two legs. You can't cut off one line and expect it to be stable."


Worst forest fires in decades

The fires are a result of the worst drought in the James Bay region in the last 40 years.

Firefighters are battling the blazes with the use of water bombers, which are attempting to extinguish the fires from above.

Three major forest fires are being monitored including one which has raged at speeds of up to 30 kilometres per hour.

Satellite images show smoke over a sizeable chunk of the northwestern part of the province. Some of the smoke could even be detected this week hundreds of kilometres away, in Montreal.

Similar fires caused power interruptions Wednesday as well, including some who were trapped in elevators and on rides at the La Ronde amusement park.