(CBS/AP) Residents warily watched as rivers continued to rise Thursday from heavy storms that killed more than a dozen people and dumped as much as a foot of rain on the Midwest.
While the first day of spring brought much needed sunshine Thursday to Ohio and other states, authorities warned that many rivers would crest well above flood stage in the next several days.
The death toll rose to at least 15, after authorities said a man drove his pickup truck into floodwaters in southeast Ohio and drowned early Thursday. Two other people died in the flooding in Ohio.
Many areas remained flooded Thursday.
Drivers trying to reach downtown Columbus from the south were being detoured off heavily traveled U.S. 23 because its northbound lanes were flooded at Interstate 270, an outer-ring highway.
President Bush declared a major disaster in Missouri on Wednesday night and ordered federal aid to supplement state and local recovery efforts in areas affected by flooding. Seventy counties and the city of St. Louis also are eligible for federal funding for emergency protective measures.
Several areas in Missouri were bracing for record-level flood surges expected to hit Friday and Saturday. Authorities were straining to keep pace with some of the worst flooding to hit their region in decades.
Throughout the low-lying areas of the state, hundreds of homes are under water. About 600 have been evacuated, reports CBS News correspondent Hari Sreenivasan.
Some residents had already been evacuated Thursday. The Black, Big and St. Francis rivers in southeastern Missouri also were expected to see significant flooding.
The town of Fenton put out a call asking volunteers to help put down sandbags against the floodwaters Thursday. Gov. Matt Blunt said cities can count on the state for help as he activated the Missouri National Guard.
"Missourians should know that we are doing everything within our power to provide state resources to communities in need," Blunt said.
In Ohio, the Scioto River reached 6 feet above flood stage, isolating homes, cutting off roads and closing major highways, reports CBS News correspondent Cynthia Bowers.
Across the lower half of the state levees couldn't hold back rising tides, and residents raced to salvage valuables from flooded homes.
"It'll definitely bring tears to your eyes when you're watching your house and praying it don't go," Cindy Kuhlman told Bowers.
Much of Ohio was under a flood warning Thursday, with some areas cautioned to watch for flash floods. Most of southwest Ohio had received more than 4 inches of rain, and officials in Butler County declared a state of emergency because of the rising waters.
The Great Miami River, west of Cincinnati near the Indiana state line, crested at 25.85 feet Wednesday at Miamitown. That's the fourth highest level since 1959, when record-keeping began at that location, said Mike Gallagher, a National Weather Service meteorologist in Wilmington, Ohio.
Flooding along the Scioto River in Pickaway, Ross and Pike counties was expected to be the worst since January 2005. The river near Circleville was expected to remain over the 14-foot flood stage through Sunday, and Pickaway County authorities asked the Red Cross to prepare shelters for possible flood victims.
In Findlay in northwest Ohio, authorities closed off streets Wednesday after the Blanchard River had again gone over the 11-foot flood level - the 10th time it has done so in the last 15 months. The National Weather Service predicted the river would crest Thursday afternoon at 12.3 feet.
"It is going to take some time to dry out with this type of rain put down on saturated ground," said Beverly Poole, a meteorologist with the National Weather Service office in Paducah, Ky. "It's going to take a few days for the rivers and the creeks to recover."
The Ohio River at Cincinnati was expected to rise about 2 feet above flood stage by Friday. In nearby Whitewater Township, rescue workers with boats helped 16 people to safety and urged 40 to 45 more families to leave their homes.
Judy Booth, who's lived in a low-lying area of the township for 11 years, said Wednesday was the first time she's had to flee from flooding.
"You don't have no choice, you've got to go," said Booth, who was helped by fire-rescue squads who brought an inflatable boat to her water-surrounded home.
Retired truck driver George Slayton, 65, said he just wasn't sure how much water from the Black River flowed into his home in Piedmont, Mo. He only had time to grab some medication and a change of clothes.
"I believe in God and everything, but he does things sometimes that make you wonder," said Slayton, who found shelter at a church and slept on a padded pew.
At least 15 deaths have been linked to the weather over the past few days, and three people were missing.
Five deaths were blamed on the flooding in Missouri, five people were killed in a highway wreck in heavy rain in Kentucky. In Ohio, a 65-year-old Ohio woman appeared to have drowned while checking on a sump pump in her home. Another Ohio woman, whose car was swept away by floodwaters near Wilmington, had clung to a tree for hours before she was rescued but died a short time later at a hospital Wednesday.
In southern Illinois, two bodies were found hours after floodwaters swept a pickup truck off a rural road.
Searches were under way in Texas for a teenager washed down a drainage pipe, and two people were missing Thursday in Arkansas after their vehicles were swept away by rushing water on Tuesday. Flood water remained standing in many places in Arkansas Thursday.