DENVER – A snowstorm moving across the Midwest forced about 60 students to spend the night at their Colorado school when a state highway was closed due to dangerous conditions that left some drivers stranded in their cars, as winter weather continued to cause problems for a wide swath of the country.

Tens of thousands remained without power in Michigan, while adverse conditions continued to disrupt flights at Chicago's O'Hare Airport. In eastern Wisconsin, hundreds of vehicles were stranded or ended up in crashes as a winter storm made travel dangerous. And in Kansas, the latest snowstorm to hit the state was being blamed for six deaths.

According to the air traffic tracking website FlightAware.com, about 100 flights in and out of Chicago's airports have been canceled for Wednesday. Flights into O'Hare International Airport are being delayed an average of about an hour.