(Reuters) - Towns in Tennessee and southern Illinois prepared on Thursday to cope with potential flooding after rain-swollen rivers washed out hundreds of structures in Missouri, Arkansas and eastern Oklahoma and forced thousands to flee their homes.

As of Thursday morning, some 9.3 million people nationwide were in areas with flood warnings. That was down from 12.1 million on Wednesday and 17.7 million on Tuesday.

At least 28 people have died in the U.S. Midwest since the weekend in the rare winter floods, mostly from driving into flooded areas after storms dropped up to 12 inches (30 cm) of rain, officials said. Flooding in the Midwest usually comes in the spring as snowmelt swells rivers.

While floodwaters from a number of rivers began to recede on Thursday around St. Louis, towns farther down the Mississippi hoped their levees would resist rising river levels. Southern states like Louisiana will be affected in coming days, the National Weather Service said.

The days of downpours have pushed the Mississippi and its tributaries to record highs or levels not seen in decades, the NWS and local officials said.

Workers in Tennessee were preparing on Thursday for the Mississippi River in Memphis to reach flood stage over the weekend.

“We’re moving things up high and we’ve got our generators out and got some extra water,” said Dotty Kirkendoll, a clerk at Riverside Park Marina on McKellar Lake, which feeds off the Mississippi River.

The Mississippi, the second-longest river in the United States, is expected to crest in the small town of Thebes, in southern Illinois, at 47.5 feet (14 meters) on Sunday, more than 1-1/2 feet above the 1995 record, the NWS said.

Thebes village worker Bobby White said some sewage pumps were shut down to avoid overloading and that portable toilets had been supplied to affected areas. Most homes in the town, including his own, are on a hill and should be fine, he said.

“Most of the people at the bottom of the hill moved out years ago,” White said.

The floodwaters have closed sections of major trucking routes Interstate 44 and Interstate 55, with the latter expected to partially reopen on Thursday evening, the Missouri Department of Transportation said.

The U.S. Coast Guard issued a high water safety advisory on Thursday for more than 560 miles (900 km) of the Lower Mississippi River from Caruthersville, Missouri, to near Natchez, Mississippi.

Louisiana Governor Bobby Jindal declared a state of emergency to prepare for flooding.

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“All that water’s coming south and we have to be ready for it,” Lieutenant Governor-Elect Billy Nungesser told CNN. “It’s a serious concern. It’s early in the season. We usually don’t see this until much later.”

BLEAK NEW YEAR’S EVE

Parts of Missouri turned into a vast lake this week, with water up to the rooftops in some towns. Two rivers west of St. Louis crested at historic levels. Sewer plants were disabled and hundreds were forced from their homes.

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Mayor Kevin Coffey of Eureka, west of St. Louis, said his town had not seen such bad flooding in 150 years and some of its oldest businesses had been damaged.

It was a bleak New Year’s Eve for evacuated people.

Tony Bellis, 51, had to leave his house in Arnold, Missouri, southwest of St. Louis, when the city shut off power in case of flooding.

Bellis’ home, where he runs his Smelly Pirate Firearms business, did not get flooded. But he spent two cold nights in his truck because he was nervous about people looting his property.

“I haven’t slept since Tuesday, because there was no electricity and I’ve been sleeping in my truck. I’m heading to Denny’s for dinner, that’s the big excitement,” said Bellis, who moved to a hotel on Thursday.

He said he lived through similar flooding in 1993.

Tom Rolfes, owner of Tom’s 100 West Irish Pub in Manchester, Missouri, said two people displaced by flooding in nearby Valley Park stopped in on Thursday for a drink and stayed for three or four.

The Meramec River broke the previous record high by more than 4 feet (1.2 meters) on Thursday morning in Valley Park, but the levee was sound and the water level quickly dropped by more than 2 feet (0.6 meter) by the afternoon.

“The water came up so damn fast. The day before yesterday, they were saying it is going to crest tonight, everything is fine, then yesterday they are saying everyone has got to get out of here,” Rolfes said. “I have never seen it like this.”