SOUTH BEND, Ind. -- Authorities were working frantically Monday to reach motorists in snow-covered northwest Indiana who were trapped in their cars in biting temperatures.
LaPorte County sheriff's Deputy Andy Hynek said officials don't know how many people were stranded, but that some had been stuck for as long as 12 hours and many were in a 10-mile stretch of U.S. 30.
"All the way across U.S. 30 is at a standstill and all of those vehicles are occupied," Hynek said.
The National Weather Service issued a winter storm warning for parts of northern Indiana, where heavy lake effect snow was expected to drop an additional 5 to 10 inches of snow Monday. Overnight temperatures had dipped into the low 20s with wind chills around 5.
Indiana authorities were having a hard time reaching motorists as snow plows struggled with the high drifts and roadways that were clogged with nearly 100 abandoned cars and some jackknifed semitrailers. But the wind was causing the greatest trouble.
"As soon as the plows go through an area, the wind is blowing fresh snow right back into the roads," state highway department spokesman Jim Pinkerton said. "It is just really difficult for us to keep up against that wind and snow."
LaPorte and Porter counties issued emergency orders telling drivers to stay off the roads as the area had winds up to 30 mph.
"The problem is people are leaving their houses for reasons that they don't need to leave," Hynek said. "That's why we issued the state of emergency."
The lake-effect snow in Indiana was separate from the powerful weekend storm that carried snow and high winds across much of the upper Midwest, said National Weather Service meteorologist John Taylor.
Flights were canceled and major highways had been closed in several states. Schools in Indiana, Michigan, Wisconsin and other states shut down Monday because of the snow and low temperatures.
That storm was headed northeast toward Canada, according to the National Weather Service, with some snow possible Monday in Michigan and through parts of Pennsylvania and New York. Nearly 2 feet of snow fell in parts of Minnesota and Wisconsin during the weekend.
In Minneapolis, heavy snow caused the inflatable roof of the Metrodome to collapse Sunday. Video inside the stadium aired by Fox Sports showed the inflatable Teflon roof sagging before it tore open, dumping massive amounts of snow across one end of the playing field.
No one was hurt, but the Vikings' game against the New York Giants had to be moved to Detroit's Ford Field. The day of the game had already been pushed back from Sunday to Monday because the storm kept the Giants from reaching Minneapolis on time. Stadium officials were trying to repair the roof in time for the Vikings' next home game, Dec. 20 against Chicago.
In the Chicago area, only a few inches of snow fell, but wind gusts of up to nearly 50 mph blew the roof off a building at Navy Pier and canceled at least 1,375 flights at O'Hare International Airport and more than 300 at Midway International Airport. The cancelations left some travelers stranded overnight at O'Hare, where officials set up about 200 cots.
On Monday, about 75 flights were canceled, said Chicago Department of Aviation spokeswoman Karen Pride said.