Rescuers in boats continued to pluck people from rising waters in Indiana on Sunday, a day after more than 10 inches of rain deluged much of the state.
In Iowa, pumps and thousands of sandbags were sent to the Iowa City area, where officials fear a reservoir could top a spillway and flood the city of about 63,000 by Tuesday.
The Indiana flooding killed at least one person, a man who drowned in his vehicle about 50 miles south of Indianapolis, said John Erickson, a spokesman for the state Department of Homeland Security. Another person was reported missing after falling off a boat about 30 miles southwest of Indianapolis.
In Michigan, two delivery workers for The Grand Rapids Press drowned early Sunday when their car became submerged in a creek that washed out a road near Lake Michigan in Saugatuck Township, the newspaper said.
Two other people in the state were killed by falling trees, one man drowned and a woman died when high winds blew a recreational vehicle on top of her, authorities said.
And lightning struck a pavilion at a state park in Connecticut, killing one person and injuring four, state environmental spokesman Dennis Schain said.
At least one tornado hit the Omaha, Neb., area with little to no warning as people slept Sunday morning, damaging several dozen homes and businesses. No major injuries were reported.
"I'd say it was a miracle no one got killed," said Omaha Mayor Mike Fahey as he toured a heavily damaged neighborhood in the west Omaha area of Millard.
Paul Higgins, 87, said the front door blew open and he was knocked down when he checked on the storm around 2:30 a.m.
"At the time you couldn't see anything" outside, Higgins said. "It was like a fog. So much stuff blowing around."
Higgins said he and his wife sought shelter in their basement, emerging to find a tree against a house across the street and a neighboring house missing its roof.
Wisconsin Gov. Jim Doyle declared a state of emergency in 29 counties and President Bush late Sunday declared a major disaster in 29 Indiana counties, freeing up aid.
Iowa saw some of its worst flooding in more than a decade, Gov. Chet Culver said in a statement as he declared an emergency in nearly a third of the state's 99 counties, freeing up state resources.
A levee broke along the Winnebago River in Mason City, and its water treatment plant was shut down. Residents of the city of nearly 30,000 have been asked to avoid using tap water.
Officials said water levels on the Iowa River at Iowa City could be like those during the historic floods of 1993, which put much of the state underwater. The University of Iowa plans to move several classes starting Tuesday.
In areas of Minnesota near the Iowa border, officials asked residents in the Winnebago Valley to evacuate. More than 60 people were being taken to a shelter in Caledonia from a campground.
In Wisconsin, more than a dozen homes near the swollen Kickapoo River in La Farge were evacuated. The National Guard was called in to help get about 50 people out of a flooded trailer park in Ontario, Wis.
The misery in Indiana spread southward, along with the floodwaters that were trying to drain down to the Ohio River.
Crews asked about 1,500 people to leave the towns of Elnora and Plainville, about 100 miles southwest of Indianapolis, because of flooding along the White River. In Morgan County, southwest of Indianapolis, about 150 residents were taken out of a flooded nursing home.
CBS affiliate station WISH reported flood warnings were in effect for 19 different towns, many of which were to remain in place until 4 p.m. Monday.
Officials moved more than 250 patients and employees from Columbus Regional Hospital in southern Indiana. Workers pumped water out of the basement, and a couple inches of mud covered the first floor of the center, which was forced to close.
Jack Elkins, 67, said his condominium near the hospital was inundated with water in a matter of minutes Saturday night. Once the storm drains filled up, it took 15 minutes for about 8 inches of water to ruin his place.
"It looked like a river in front of my house," he said as he took a break from ripping up carpeting and flooring.
The National Weather Service warned that another round of storms could drop as much as 3 inches of rain on Indiana late Monday.
Hundreds of thousands of customers lacked power across the region, more than 300,000 in Michigan alone.
The storms popped up in central Kansas in the late afternoon and moved northeast toward Missouri, producing winds up to 80 mph and golf-ball sized hail in some areas, according to National Weather Service spotters.
One building and six cars at the correctional facility in El Dorado County east of Wichita suffered were damaged by hail nearly three inches in diameter, Butler County emergency personnel reported to the weather service.
Residents of Chicago's northern and southern suburbs spent Sunday cleaning up from at least seven tornadoes the night before. The storms tore roofs off homes, toppled power lines and overturned tractor-trailers. Several minor injuries were reported, and stretches of Interstate 57 remained closed for a second day Sunday because of downed power lines.
Meanwhile, CBS News correspondent Bianca Solarzano reported that further south along the East Coast, it was sky-high temperatures causing problems.
A record daily mercury reading of 100 degrees was registered in Richmond, Virginia, and the tripple-digit heat in North Carolina was making it difficult for firefighters to get a grip on a 30,000 acre wildfire.
The sweltering temperatures, which stretched all the way up into New York, were expected to last through Monday, reported Solorzano.