A blizzard dumped thigh-deep snow on some areas of the upper Midwest on Sunday, playing havoc with travelers and causing the roof of a large stadium, the Metrodome, to collapse in Minneapolis.

The snow hit Wisconsin and Minnesota the hardest as it moved eastward.

Blizzard and winter storm warnings were in effect for Chicago and parts of northern Illinois, Iowa, Minnesota, Wisconsin, Missouri, Michigan and North and South Dakota. Upwards of 20 inches of snow fell on some areas, the National Weather Service said.

As much as 22 inches of snow fell in the metropolitan area of Minneapolis-St. Paul, local media said.