MINNEAPOLIS â€” The inflatable roof of the Minnesota Vikings' stadium collapsed Sunday and roads were closed throughout the upper Midwest as a storm that dumped nearly 2 feet of snow in some areas continued to crawl across the region.

A blizzard warning was in effect for Chicago and much of northern Illinois, all of Iowa, large sections of southern Minnesota and Wisconsin, and smaller areas in North Dakota, South Dakota, Missouri and Michigan, according to the National Weather Service. Most of the rest of the region was under a winter storm warning or a hard freeze watch.

The Metrodome's Teflon roof collapsed after Minneapolis got more than 17 inches of snow. No injuries were reported. The snowfall that ended Saturday night was one of the five biggest in Twin Cities history, National Weather Service meteorologist James McQuirter said. Some surrounding communities got more than 21 inches of snow, he said.

Interstate 90 from Albert Lea to the South Dakota border and state highways remained closed. Plows that had been pulled off the roads Saturday began work at 4 a.m. Sunday but were struggling with drifts as high as 5 feet, Minnesota Department of Transportation spokeswoman Rebecca Arndt said. Plow drivers also were hampered by a large number of stalled cars.

"Stalled vehicles slow them up more than big drifts," Arndt said.

Although roads were open in Wisconsin, state officials urged drivers to stay home because blowing snow severely limited visibility. Tod Pritchard, a spokesman for Wisconsin Emergency Management, said travel was expected to become even more difficult in the afternoon because temperatures were falling and at a certain point, road salt would no longer be effective.

"We're really urging everyone to stay off the roads today and stay hunkered down at home," Pritchard said.

The storm had already dropped up to 18 inches of snow in parts of northern and central Wisconsin, he said, and light snow continued Sunday morning.

Some 420 air travelers spent the night in Grand Forks, N.D., after four planes were diverted from Minneapolis, where the storm had closed all but one of that airport's runways. After a traction truck broke down on the one operational runway, planes circled the airport until they had to head to other regional airports for fuel.

Some passengers stayed at the airport, others got hotel rooms.

"It was chaotic, it was crazy completely. We were packed like sardines and we were shocked," passenger Leah Edmondson told WDAZ.

The planes were scheduled to leave Grand Forks on Sunday morning.

The weather was an unexpected burden for one Minnesota man who had pledged to camp out on the roof of a coffee shop to help his daughter's school raise money.

Hospital executive Robert Stevens donned four layers of long underwear, heavy boots and a down coat before embarking on his quest Friday night. He vowed not to come down until he had raised $100,000, but after reaching the halfway mark Saturday morning, he said he hoped the rest of the money would come fast. He didn't look forward to spending another night out in the blizzard.

"I think I've crossed the line into insanity," he said. 

Associated Press writer Dirk Lammers in Sioux Falls, S.D., contributed to this report.

http://www.msnbc.msn.com/id/40628497/ns/weather