People across most of southern Alberta, including Calgary, were ducking for cover Tuesday afternoon as another powerful summer storm rolled through the area.

The storm toppled trees and knocked out power to thousands of people with reports the wind tore the roofs off a couple of homes on the Siksika First Nation.

660News listener Midge, who lives in Black Diamond, says thought it was a tornado and was preparing to head to her basement with her dog in tow.

The Calgary Fire Department reports it fielded 130 storm related calls over a 90 minute period.

Airdrie was among the hardest hit areas, with the storm knocking out power and flooding a number of roads.

Operations at Calgary International Airport were grounded for a short time, until the storm passed.

Drastic action had to be taken to rescue two window washers who were stranded on their platform outside the 22nd floor while working on a downtown high-rise.

The window they had just cleaned had to be smashed to get them inside to safety.

Alberta Transportation plans to investigate why a road sign above northbound Deerfoot Trail at 32nd Avenue came crashing down.  The video of the big sign blowing around has gone viral; to see it, click here.

660News listener Stuart was driving on Highway 1 just east of Cluny when the storm hit; check out his video of the rain and hail here.

Despite the intensity of the storm, no reports of any serious injuries.

Even though the long range forecast calls for sunny and hot conditions, Environment Canada is reminding people to always keep and eye on the sky.