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Dubbed the "Blizzard of Oz" in Kansas, the storm coursed its way through the Midwest and Plains states — collapsing roofs, forcing highway and school closures, leaving tens of thousands without power and breaking snowfall and low-temperature records.
Airlines canceled about 6,300 flights Wednesday, according to the flight tracking service FlightAware.com. About a third of the canceled flights were out of Chicago's O'Hare International Airport, one of the nation's busiest hubs. Eighty-four flights were canceled at Los Angeles International Airport.
At least two deaths were blamed on the weather. On Long Island in New York, a homeless man set himself on fire trying to stay warm, and in Oklahoma a 20-year-old woman was killed while being pulled on a sled by a pickup that crashed into a pole.
By late Wednesday, the blizzard, which pummeled Chicago with lightning, thunder and whiteout conditions, had narrowed its path along northern New England and upstate New York.
At its height, the storm had a following that more than rivaled Oprah Winfrey's Twitter audience: the National Weather Service website, which normally gets 70 million hits a day, was drawing as many as 20 million an hour Wednesday.
At one point the weather service issued blizzard warnings for an area stretching from Oklahoma City to Detroit, and wind-chill warnings from the Dakotas to Texas, said Laura Furgione, the service's deputy director. She compared the "massive storm" to the one that paralyzed Chicago in 1979 for more than a week.
Not only did 20.2 inches of snow and near-hurricane winds close Chicago schools and banks Wednesday, it kept people from so much as buying groceries or fixing an achy tooth. Denise Daly spent the morning canceling appointments at her dental office.
"Someone with a toothache can deal with it for a day as long as they have something for the pain," she said.
Although the snowfall had all but stopped Wednesday evening, it went down in the books as the third-worst storm in Chicago, and set a record for cold at minus 40 degrees in parts of Montana. Oklahoma City's 11.8 inches of snow set a new February one-day record.
President Obama received a telephone briefing on the federal response to the storm from Homeland Security Secretary Janet Napolitano and Federal Emergency Management Agency Administrator Craig Fugate. FEMA had put power generators, blankets, cots, water, meals and other emergency supplies in places that were likely to suffer the most.
"It's been a very snowy winter in general," Furgione said. "It's not over yet. We're still expecting this cold air to remain over the central United States and even the Eastern Seaboard. We are expecting more below-normal temperatures at least through the next two weeks."
For worried Super Bowl fans, predictions called for warmer temperatures by Sunday in Dallas, where an unusually severe ice storm had driven the mercury below zero and prompted utility companies to orchestrate rolling blackouts across the city, with the exception of Cowboys Stadium.
"It won't be anywhere near as cold Sunday in Dallas as it is today down there," said Bruce Sullivan, a National Weather Service meteorologist.
In New York City, the locals called it the "Groundhog Day Storm" as they gingerly negotiated icy sidewalks, and Mayor Michael R. Bloomberg had an uplifting encounter with the city's most famous groundhog, Staten Island Chuck, who, however improbably, predicted an early spring. (And you don't mess with Chuck: In 2009 he bit the mayor's hand, prompting Bloomberg to wear gloves for their next encounters.)
In Kansas City, Mo., Danny Rotert, an aide to Rep. Emanuel Cleaver II (D-Mo.), was hunkered down in his home, responding to questions via e-mail.
"The city is shut down and has declared an emergency," he wrote. "… Even if I could shovel the driveway to get out, my street would be impassable."
Some motorists were stuck for hours in their vehicles on snow-clogged highways.
On Chicago's Lake Shore Drive, nearly 1,000 cars were stranded overnight. Just before dawn Wednesday, firefighters walked down the line of snow-caked cars, shining flashlights inside to check on motorists.
Joanna Moore, 24, and her boyfriend were returning home from the Downstream Casino Resort in Quapaw, Okla., when they got caught in whiteout on the Will Rogers Turnpike. They had two cups of hot chocolate and two muffins to tide them over between 9 a.m. and 8 p.m., when the National Guard rescued them.
They were among 16 people waiting out the storm at a Red Cross shelter set up in a local church. It was unclear when the couple would be able to retrieve their car and get home. Moore said she was crossing her fingers that they would be there in time for her 3-year-old daughter's birthday Friday.
Meanwhile, officials began to prepare for an onslaught of insurance claims resulting from damaged properties like the Hard Rock Hotel & Casino near Tulsa, where part of the roof caved in.
Wet snow and heavy ice caused roofs to cave in and buildings to collapse in several states. A gas station canopy plummeted in Long Island, an airplane hanger in Boston and an entire brick building in northwest Connecticut.
Even sunny Arizona didn't escape freezing temperatures, prompting a warning from the National Weather Service for Phoenix residents to keep their plants and pets warm.
In Milan, N.H., Brad Ray, 72, who used to rescue people from avalanches on Mt. Washington, wondered what all the fuss was about.
Yes, the snow was coming down, he said, and they had already had 12 inches.
No, he wasn't rushing to plow his 1,325-foot driveway. "My plow truck is a pretty good size," he said. "I have a lot of weight and chains on it. I don't worry about pushing the snow."
But even with all his equipment and know-how, he advised: "Listen to the professionals and don't go out unless you really have to."
By Richard Simon, Geraldine Baum and Abby Sewell, Los Angeles Times