Authorities in the US have worked to reach more than 70 motorists in the snow-covered state of Indiana who were trapped in their cars in biting temperatures, as the storm was blamed for at least 11 deaths.
LaPorte County sheriff's Deputy Andy Hynek said officials don't know exactly how many people were stranded, but some had been stuck for as long as 12 hours.
The heavy lake effect snow in Indiana was part of a slow-moving storm that has been crawling across the central United States since Friday night. The storm dumped nearly 2 feet of snow before it stretched further east, with snow in parts of Ohio, Pennsylvania and New York.
The upper Midwest also has been gripped by bone-chilling cold as arctic air swept in behind the storm. Wind chills were well below freezing in many places, and schools in Indiana, Michigan, Wisconsin and other states shut down because of the snow and cold.
Indiana was hardest hit, with up to 16 inches of lake-effect snow in some areas. Lake effect snow develops when cold air rushes over the warmer water in the Great Lakes.
About 70 vehicles were trapped by snow drifts on a section of highway in the Valparaiso area. Police said they were found warm and safe in their vehicles.
Crews were using front-end loaders to remove drifts on US 30, where other drivers were trapped by overnight, state highway department spokesman Jim Pinkerton said.
Sections of two highways were closed, and with winds of up to 30 miles per hour, LaPorte and Porter counties issued emergency orders telling drivers to stay off county roads as well.
At least 11 deaths in four states have been attributed to the storm. Four people died in road accidents, and a 79-year-old man western Wisconsin was killed when a plough truck backed into his driveway and hit him.
Four men in Michigan and one in Minnesota died while shovelling snow, and Kennenth Swanson, 58, of rural Wisconsin, died when a metal shed collapsed from the heavy snow, pinning him under debris and about 3 feet of snow.