Severe flooding in the midwest and southern plains had claimed at least 20 lives Monday, after relentless thunderstorms dropped up to a foot of rain on parts of Minnesota and Wisconsin and heavy rains left over from Tropical Storm Erin soaked Oklahoma and Texas.

Rising floodwaters caused six deaths in southeastern Minnesota, six deaths in Oklahoma, and eight in Texas. One man remained missing in Minnesota Monday, where the rains set off mudslides and caused flooding Sunday that forced evacuations of entire towns.

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In Minnesota, where National Guard soldiers guarded the small towns that cleared out following the flooding early Sunday, rescue workers in Winona County resumed the search for a 37-year-old man whose car was found upside down next to Rush Creek behind the rest stop along Interstate 90 near the exit to Lewiston.

The Winona County Sheriffs Dive Rescue Team was at the rest stop Monday morning preparing to search the north branch of the creek. Divers in wet suits were there, and an inflatable raft was ready to go into the water.

Dive team leader Russ Marsolek said it appeared the car was driving on a gravel road when it crossed a bridge over the creek and was swept away, eventually settling along the creek more than 100 feet below the rest stop. The two-door Grand Prix was turned upside-down with the front bumper ripped off, its license plate mangled.

Marsolek said the victim is believed to have been wearing camouflage clothing, making the search more difficult.

"This is the worst disaster that's hit southeast Minnesota in a lifetime," state Sen. Sharon Erickson Ropes said.

Two victims of the flooding in Houston County were identified Sunday night: David Roland Ask, of Houston, who was killed in Mound Prairie Township; and David Thomas Blackburn, of Spring Grove, who died in LaCrescent Township.

The Star Tribune of Minneapolis reported Blackburn, 37, died after his foot became wedged between his vehicle and a tree after his car carrying his wife, Dawn, and a friend was swept off County Road 6 by high water.

He helped his wife and their friend into a tree before he and the vehicle were swept away, according to Dawn's aunt, Lori Stoen, of Spring Grove. The Blackburns had two young sons. Both worked in Caledonia at Miken, a baseball and softball bat maker.

Winona County Sheriff Dave Brand said Victor Gensmer, 80, and his wife Joyce, 68, drowned near Witoka when County Road 17 gave way in front of them. John Micheel, 67, and his wife Shirley, 66, of Lewiston, died when their car was washed into a ditch in Stockton, the sheriff said.

Houston County officials, meanwhile, also said Sunday night that search and rescue operations were under way in many parts of that county.

County Engineer Marcus Evans, county engineer, spoke for Houston County Highway Department, said 10 of the county's 34 County State Aid Highways were closed as of Monday morning. He told motorists: "Be careful out there. There are areas that we do have some major concerns in, and we don't want to lose anybody else."

Among the hundreds of people evacuated were several who spent a harrowing night on their rooftops, including Sean Wehlage and his girlfriend.

"I cannot describe the terror of it all. I'm just glad to be alive," said Wehlage, 29, who climbed onto the roof of his one-story home in Stockton.

In Brownsville, eight people survived as their houses were pushed over a bluff by a mudslide, according to the Winona Daily News.

Gov. Tim Pawlenty ordered 240 National Guard soldiers to the area to help with flood-relief and provide security.

The governor declared a state of emergency in six counties -- Winona, Wabasha, Fillmore, Houston, Steele and Olmsted. That will allow the state to coordinate response efforts, including using the Army Corps of Engineers to use pumps and generators to avoid levee breeches along the Root and Mississippi rivers.

Pawlenty toured flooded parts of Houston County on Monday, and was scheduled to meet with county residents who had been evacuated.

The Houston City Council ordered an evacuation of the town of 995 people, although that order was lifted Monday morning. City officials said any significant rainfall in the next few days could force them to reissue the evacuation order. Stockton, with 803 residents, was evacuated, as well, and evacuations also took place in Pickwick and Elba and parts of Winona, which sits on the Mississippi River.

The Red Cross set up a shelter at St. Mary's University in Winona, St. Charles High School and other locations throughout the area.

Houston County Sheriff's dispatcher Dwayne Beckman said several roads and highways had been closed, bridges were washed out and mudslides were reported countywide. Grassy areas near Highway 16 outside Caledonia had been reduced to muddy lakes. Trees had slid toward stretches of Highway 44 between Caledonia and Hokah.

Tim Comstock, public information officer for Houston County, said Monday that county officials were assessing the dike along the Root River in Houston to see when it would be safe for residents to return.

National Weather Service Meteorologist Tod Rieck in La Crosse, Wis., said a storm system that parked over southeastern Minnesota and southwestern Wisconsin dumped 6 to 8 inches of rain on Saturday, with some areas receiving as much as a foot.

"When the showers and thunderstorms set up, they sat there for hour after hour after hour," he said.

He said the Kickapoo river in Wisconsin was at a record crest on Sunday, and the Root River in Minnesota was at or near a record crest.

In Rushford, the power and phone service was knocked out and the sewage treatment system was under water, said Fillmore County coordinator Karen Brown.

To help drain away the water, the U.S. Army Corps of Engineers opened part of its lock and dam system on the Mississippi River south of Lake Pepin -- a bulge in the river in southeastern Minnesota.

"Once we pull the gates, it's open river conditions," said Shannon Bauer, corps spokeswoman. "It's like the dams are not there."

The weather service warned of more heavy rain across the southern third of the state on Monday, including thunderstorms in the southwest corner of the state.

High Water in Wisconsin

Weekend thunderstorms that dropped more than a foot of rain in southwestern Wisconsin caused millions of dollars in damage, forced evacuations from flooded homes, and washed out roads and bridges.

There were no reports of injuries. The hardest hit areas were in Crawford, Grant, La Crosse, Richland and Vernon counties, said Wisconsin Emergency Management spokeswoman Lori Getter.

Gov. Jim Doyle declared a state of emergency in Crawford, Richland and Vernon counties, where he surveyed the damage by car Monday morning.

In Crawford County, Doyle examined a partially collapsed road in Soldiers Grove and ventured into Gays Mills' evacuated downtown, gazing at knee-deep water on Main Street. A total of more than 200 homes were flooded in the two towns, each with about 600 to 640 residents, Getter said. Some houses had water 4 feet deep.

Doyle listened to Gays Mills' village president Larry McCarn describe how firefighters started going door-to-door at 2 a.m. Sunday to warn residents.

It was amazing how fast the peanut butter-colored water rose, McCarn said.

"We were in deep doo doo then," he said.

By midmorning, the water had visibly receded in Gays Mills, and emergency officials began letting some people return to their homes to salvage their belongings. Residents were being allowed in if they didn't have to walk through water, village trustee Mike Heisz said. They could take only what they could carry and could not remain in their homes.

Doyle promised to seek federal aid but said he was more worried at the moment about dams in the area giving way and forecasts calling for more rain.

"Right now, people are still in the middle of this," the governor said.

The state estimated Vernon County had at least $9.5 million in damage, Doyle said during an earlier stop in Viroqua. That number is likely to rise as damage reports continue to come in, he said.

Crawford County had an estimated $11.4 million in damage, including $3.6 million to highways, almost $4.8 million to homes and about $3 million to businesses, said Gary Knickerbocker, spokesman for Crawford County emergency management.

Richland County had an estimated $3.1 million in damage, said Donna Gilson, a spokeswoman at emergency management's Madison headquarters. Damage estimates for the other counties had not been issued Monday morning.

Both Vernon and Richland counties had about 30 homes damaged with two or three destroyed, Gilson said. Those numbers also were expected to increase.

Doyle ordered the emergency management office to lead the state's response efforts, and directed all state agencies to assist the affected communities.

Nearly 80 people living near the Clockmaker, Duck Egg, Hidden Valley, Primmer, Raaum, Runge Hollow and Seas Branch dams in Vernon County were evacuated, Gilson said. The Seas Branch and Hidden Valley dams were reportedly leaking, and county officials were warning people to stay out of the areas.

The Wisconsin National Guard armories in Richland Center and Viroqua were opened, and its staff was assessing what it could do to help.

Light rain continued to fall in southwestern Wisconsin Monday morning, after up to a foot Saturday night and early Sunday.

Dave Schmidt, a meteorologist for the National Weather Service in La Crosse, said a flood warning for portions of southwest Wisconsin remained in effect until about 3 p.m. Monday. But more rain was in the forecast and it was possible a flood watch would be issued later Monday, he said.

Flooding could remain a problem through Friday, given the storms expected to travel through the area, he said.

"We do have an organized line of storms going through northwest Iowa now," Schmidt said Monday morning.

Emergency officials evacuated 66 people from one nursing home in Soldiers Grove to other nursing homes around southwestern Wisconsin.

They also evacuated 23 people from an apartment complex in Soldiers Grove.

Southwestern Wisconsin is also known as the Driftless Area, a swath of the state untouched by glaciers. The terrain is rugged and wild with farm fields interspersed in valleys between towering bluffs and ravines.

Signs of the flooding were stark throughout the region Sunday afternoon. The bluffs and hillsides were pockmarked by mudslides and tree limbs covered the roads.

A mudslide in Vernon County pushed a house onto state Highway 35, forcing emergency officials to close the highway, Gilson said.

Five cars of a 65-car train sitting on tracks a half mile south of Goose Island in Vernon County derailed and the area around the derailment was evacuated, Getter said. One car that contained acid tipped over, but hazardous materials teams didn't detect any release of the substance, she said.

Oklahoma Clean-Up

Gov. Brad Henry declared a state of emergency Monday in 24 counties damaged Sunday when the remnants of Tropical Storm Erin brought high winds and heavy rain to the state, flooding hundreds of homes and businesses and killing six people.

Henry's declaration was the first step toward seeking federal assistance. The Oklahoma Department of Emergency Management was making preliminary damage assessments.

An estimated 150 homes and businesses were damaged near Kingfisher, the first stop on the governor's tour of flooded areas Monday. In Caddo County, an estimated 150 homes had been damaged or destroyed, officials said.

Other damage was reported in Blaine County, where mobile homes were blown apart, an airport hangar was damaged and a light airplane was turned into twisted metal.

"The response of Oklahomans to this disaster has, as usual, been exemplary," Henry said. "First responders on the state and local level acted quickly, heroically and decisively to save lives and ease the pain of those affected by these storms."

The counties included in the state of emergency are: Blaine, Caddo, Canadian, Cleveland, Comanche, Cotton, Custer, Dewey, Grady, Jefferson, Kingfisher, Kiowa, Lincoln, Logan, McClain, Muskogee, Okfuskee, Oklahoma, Okmulgee, Pontotoc, Pottawatomie, Seminole, Stephens, and Washita. More counties will be added as needed.

Eight Dead in Texas

Authorities over the weekend found the body of a man who was swept into a creek in Kendall County during storms that were the remnants of Tropical Storm Erin.

Searchers found the body of Juan Pablo Zaragoza, 28, on Saturday afternoon less than a mile from where the truck he was in with his father got washed off a bridge and into a creek. Authorities found the body of the father, Juan Ramon Zaragoza, 48, on Friday.

At least six other people died in the storms and flooding left over by Erin.

The storms in Houston killed three people, including two died when a roof over a grocery store's storage unit collapsed. The third victim was a trucker who drowned when his 18-wheeler went into a deep retention pond.

In San Antonio there were two deaths. A man was swept away by floodwaters after he got out of his car. His body was found about three miles downstream. And authorities found the body of a woman swept away after her vehicle went into a drainage ditch.

In Taylor County, searchers on horseback found the body of Rita Johns on Saturday afternoon, hours after her vehicle was found washed off the road in an area called Coronado's Camp.

Also in Taylor County, after about 2,000 houses in Abilene were evacuated, residents were allowed to return and all streets were reopened Sunday night as floodwaters began to subside, said city spokeswoman Lenka Wright. A handful of houses and businesses were damaged when Elm Creek spilled from its banks after heavy rainfall.

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