People across the Midwest woke up Thursday to as many as 20 inches of snow, while residents and business owners in the Great Lakes region nervously eyed rising rivers and braced for flooding.

Flood warnings were issued in Illinois, Indiana, Ohio and New York after three days of heavy rain and melting snow. People in northwest Ohio moved to higher ground as forecasters predicted that floodwaters would continue to rise in an area still recovering from flooding five months ago.

"You don't get used to it, you just deal with it," Linda Crace of Findlay, Ohio, said Wednesday as she emptied her basement and garage, putting a lawn mower on her porch, boxes of clothes in her dining room and a washer and dryer in the kitchen.

Meanwhile, residents across the Midwest were digging out from a major snowstorm that closed schools and businesses and brought travel to a standstill. Hundreds of flights were grounded in Illinois and Wisconsin, and traffic backed up for 19 miles south of Madison after semitrailer trucks got stuck on a hill.

Gov. Jim Doyle called a state of emergency late Wednesday, sending National Guard troops to help about 500 vehicles stuck in the jam blocking Interstate 90. Snowmobiles and all-terrain vehicles were already being used to check on the stranded motorists and bring them food or fuel.

Capt. Lee McMenamin of the Wisconsin State Patrol said late Wednesday that vehicles were gradually trickling out of the backup as the semis were being freed, one by one.

Blustery winds created near-whiteout conditions in southern Wisconsin, where slick roads were blamed for two traffic deaths. Snowplow operators were called off the roads shortly before noon in Green County, highway Commissioner Dallas Cecil said.

"The winds are blowing so hard the guys can't see the front of their trucks," he said.

Occasional periods of blizzard-like conditions developed along the Lake Michigan shoreline from Milwaukee to Kenosha as the snowfall picked up Wednesday, said meteorologist Rusty Kapela of the National Weather Service's Sullivan office.

By the time the storm wound down, 21 inches of snow had fallen near Beloit, in south-central Wisconsin, and a little more than 20.1 inches at Saukville, north of Milwaukee.

All flights were stopped at General Mitchell International Airport at Milwaukee, airport spokeswoman Pat Rowe said.

At Chicago's O'Hare International Airport, about 900 flights were canceled as of 9 p.m., with delays up to three hours, said Karen Pride, spokeswoman for the city's aviation department. Across the city at Midway Airport, there were 130 cancellations, with delays on remaining flights of about 90 minutes, Pride said.

Ethel Iles thought she was playing it safe by flying from Rochester, N.Y., to Detroit instead of driving. But she had to fly through O'Hare, where she hunkered down Wednesday night after her flight was grounded amid 4 inches of snow.

"I didn't want to drive because you know how much snow they get in Ontario and western New York," Iles said, waiting to catch a Thursday flight.

Nearly a foot of rain, ice and snow fell across northern Illinois, keeping thousands of students home from school. Classes were also canceled Wednesday in parts of Kansas, Iowa, Wisconsin and Michigan, where up to 14 inches of snow fell north of Detroit.

Officials in Indiana and Ohio were especially concerned with flooding. The National Weather Service warned Wednesday that the Wabash, Tippecanoe and other major rivers in Indiana had spilled their banks.

Rising waters from the Blanchard River in Findlay, Ohio, were another blow to residents and business owners just getting their lives back to normal after flooding in August displaced hundreds and caused millions of dollars in damage.

"We had the place completely gutted," music store owner Scott Adams said as he loaded equipment into a trailer to try to keep it dry. "I don't see fixing the place again."

The river was 4 feet above flood stage Wednesday afternoon and was expected to keep rising until Thursday morning, when it could eclipse 5 feet above flood stage, said Jim Barker, the city's safety director.

The flooding wasn't expected to be as bad as August's — the city's worst since 1913 — but firefighters evacuated a handful of residents.

Water started spilling into downtown Wednesday afternoon, forcing the city's main thoroughfare to close where several storefronts remain empty from the last flood. Within a few hours, the entire street was covered by water, and at least 100 homes had suffered some water damage, Barker said.

In Wapakoneta, in the state's northwest, firefighters removed about 30 people from their homes and businesses Wednesday because of high water. A foot of water surrounded one trailer park, fire chief Kendall Krites said.

By afternoon, the state Department of Transportation had closed 88 state and federal routes in eight northwest Ohio counties, with most remaining closed into the night.

High school students in Pemberville, near Toledo, helped build a sandbag wall to try to protect the downtown business district from the rising Portage River.

In southern Ohio, emergency officials monitored the Ohio River's rising waters.

East of Cincinnati, winds tore one roof off a motel in Aberdeen and another off a gardening store in Bethel.

In northwestern Indiana's Newton County, divers spotted at least one body in a vehicle submerged underwater in a quarry. The car may have plunged into the icy water overnight, Indiana Conservation officers said. A diver was unable to open the car doors, and the recovery effort was postponed until water could be pumped out, they said.

In upstate New York, freezing rain and snow contributed to a pileup that killed one person and sent another to a hospital, authorities said.

The crash, which occurred on Interstate 81 near Mexico in Oswego County, 25 miles north of Syracuse, closed the highway's northbound lanes for more than four hours Wednesday night.