08/15/2012 05:36 EDT

Summer Storms Wreak Havoc On City And Surrounding Areas (PHOTOS)

amandamarie403, Twitter

It's been a week of harrowing weather even for Alberta standards, as violent storms sparked mass power outages, severe hail damage and even a narrow escape by two Calgary window washers.

The most recent bout of severe weather tore through Calgary and surrounding areas late Tuesday, wreaking havoc on residents, buildings, vegetation and cars, and causing a narrow miss for two window-washers.

The rapid darkening of the sky with menacing clouds signalled the onset of the storm, prompting many on Twitter to document the pending downpour. Joshua Zhivago captured the ferocity of the weather on video (click on the link in the tweet to watch):

Witnesses saw trees felled in their yards and onto the streets and watched as sheets of rain pummelled their homes. The Calgary Herald reported that the fire department responded to 130 calls in 90 minutes, with downed power lines and overturned trucks among the incidents, and 25,000 residents in various areas losing power.

Two window washers found themselves in a precarious and terrifying predicament on their scaffolding when they were caught in the storm. The pair was forced to break a window of the building to take shelter, sustaining only minor injuries, CTV reported.

And drivers on Deerfoot trail watched in disbelief as a highway sign was torn off its posts and fell to the ground.

Tuesday's storm came on the heels of an intense hailstorm Sunday night, which caused severe damage to cars around the city, and which had residents doing cleanup right up to the second storm, according to the Calgary Sun.

Story continues below slideshow:

All Hail Calgary Weather!

Calgary isn't the only city that's suffered from summer storms.

An agency that tracks insured losses says last month's big thunderstorm in Edmonton caused damage estimated at more than $100 million.

Property Claims Services Canada says thousands of insurance claims have been filed since the July 12 storm rolled through the city.

South Edmonton was hit the hardest. Homes and businesses were flooded, vehicles were submerged on roads and hail the size of quarters caused property damage.

Heather Mack with the Insurance Bureau of Canada's Alberta branch says it's astonishing how much damage a storm can cause in a short period of time.

She points to a report prepared for the insurance industry that projects more unsettled weather including hail, thunderstorms and wild fires.(CHED)

With files from The Canadian Press