At least three people are dead after severe weather swept across the upper Midwest and Canada Friday. It's the latest bout of severe storms after a quiet start to the spring, CBS News' Vladimir Duthiers reports.

Powerful winds toppled trees, peeled back rooftops and sent boxes flying across an airport runway in Toronto, and wind gusts of more than 60 mph sent a sky crane spinning in the city.

The Great Lakes region was under an aerial assault for much of Friday with deadly results. A man was killed northwest of Detroit when part of a tree snapped and fell on him while he was working in a yard.

"Who would've ever thought?" one woman said. "I mean, we all have the big trees in the yard. No one would have ever thought that. It was very sad, very sad."

A man in Canada died after witnesses saw him trying to clear downed wires from a roadway, while another was killed by a falling tree.

Nearly half a million customers in the U.S., from the Great Lakes to New England, lost power. Another 100,000 in Canada lost power as well.