CHICAGO (AP) — Mother Nature apparently saved the best, or at least the biggest, for last.
The storm rolling into Chicago on Tuesday was expected to dump as much as 10 inches on the city, the most since the 2011 blizzard and its more than 20 inches of snow.
"This will be the biggest widespread storm of the winter," National Weather Service meteorologist Amy Seeley said.
The storm started Sunday in Montana, hit the Dakotas and Minnesota on Monday and then barreled through Wisconsin and Illinois on its way to Washington, where it was expected late Tuesday night.
Schools were closed in Minnesota, Wisconsin and Illinois, where officials urged caution on snow-slickened roads. In western Wisconsin, a semi-trailer slid off a snow-covered interstate near Menomonie and into the Red Cedar River, killing one person. Authorities said they were searching for a second person, believed to be a passenger.
Airlines canceled nearly 1,000 flights at Chicago airports, prompting delays and closures at others around the region.
Hardware stores in and around Chicago did a brisk business, selling salt and snow shovels at a time when many usually turn their thoughts toward gardening and baseball.
"Everybody's got a little comment with every bag they're buying," said Mike McIntosh, who works at Dressel's Hardware in Oak Park just outside Chicago. Workers had started to stock the shelves with tools and supplies associated with spring and summer, only to find the shovels and salt they thought they'd hold for another year were still in demand.
"Everybody's a bit surprised, but it's good for us, we've got a lot of this stuff to move," McIntosh said Monday.
A wet snow pelted commuters as they slid along the slick streets of downtown Chicago through the soggy wintery mix early Tuesday. Snow was forecast for the morning and afternoon rush hours, Seeley said. The weather service also said that as much as 1.5 inches of snow could fall per hour, "making snow removal difficult and travel extremely dangerous."
Ill. Gov. Pat Quinn urged motorists to avoid driving unless absolutely necessary, insisting that "safety comes first."
The Illinois Department of Transportation planned to send a fleet of 360 trucks to plow roadways in northeastern Illinois early Tuesday, with a total of 600 throughout Northern Illinois.
The storm created wet, heavy snow — known euphemistically as "heart attack snow" — which can pose a risk when it comes time to shovel for the elderly, sedentary people or those who have heart problems.
"Shoveling snow is a lot of work. ... It is taxing their bodies and their hearts," said Dr. David Marmor, a cardiologist at NorthShore University HealthSystem in Evanston. "People are really testing their limits, and if they're already at high risk they are better off paying the kid across the street to do it."
If Chicago gets 10 inches of snow, it would only underline that this has been a mild winter, Seeley said. That amount would raise the snowfall this season from 20.3 inches to 30.3 inches — just a tenth of an inch more than what Chicago sees in a typical winter.
In northern Iowa early Tuesday, at least one person was enjoying the gentle snowfall.
"It's absolutely gorgeous out," said Mary Hermanson, the night shift front desk clerk at the Super 8 in Mason City.
"If I'm going to have snow come down, that's what I want to have come down," she said of the 10 inches that had fallen in the area in the past 24 hours. She happily said it reminded her of Christmas.
Associated Press writers Nelson Lampe in Omaha, Neb., and Gretchen Ehlke in Milwaukee contributed to this report.