Paul Beaty, Associated Press
Aerial photo shows a break caused by floodwaters in a levee north of Quincy, Ill.

OAKVILLE, Iowa — Even before the Iowa River used this town as a shortcut to the Mississippi, there wasn't much here: a post office, a convenience store, a tavern and a little restaurant.

The largest employer was a pork-and-grain producer called TriOak Foods. The company's towering grain elevator was the tallest structure for miles around.

Then the floodwaters soaking much of the Midwest turned their force on the region's small communities — most with skylines that consist only of a water tower and maybe a couple of church steeples.

As the rivers rise, these modest towns survive because neighbor helps neighbor, and the people reinforcing the levees are business owners, farmers and fellow church members who have lived there for years.

"My house is past help. So we're trying to save everybody else's," said Bethany Frank as she helped fill sandbags in a church parking lot in Oakville, about 40 miles southwest of Davenport. Her home on the outskirts of town was flooded up to the roof.

On Wednesday, Iowans assessed their losses from flooding that inundated Des Moines and Iowa City. But small towns up and down the Mississippi still awaited the worst of the flooding. Some rivers were not expected to crest until Thursday.

Storms and flooding across six states this month have killed 24 people, injured 148 and caused more than $1.5 billion in estimated damage in Iowa alone — a figure that's likely to increase as river levels climb in Missouri and Illinois.

Federal officials predicted as many as 30 levees could overflow this week, leaving industrial and agricultural areas vulnerable but sparing major residential centers. So far this week, 20 levees have overflowed.

At least 10 levees have been topped in Illinois and Missouri in recent days, including two south of tiny Gulfport, Ill., that threatened to swamp 30,000 acres of farmland near the evacuated town of Meyer, Ill.

A 280-mile stretch of the Mississippi River remained closed between Fulton, Ill., and Winfield, Mo., because of flooding, and is expected to remain closed for at least 10 more days. Lynn Muench, of the towboat and barge trade group The American Waterways Operators, said as many as 10 tows — each with as many as 15 barges — were stuck on the upper Mississippi River.

Missouri Gov. Matt Blunt sent 600 members of the National Guard to the northeastern part of the state, plus another 100 to the St. Louis area to help towns further downstream. In Illinois, 1,100 Illinois National Guard troops have been sent to help flooded communities.

"My property is right on this street. I've got a lot to lose," said Tony Dye, whose home in Canton, Mo., stands beneath the levee and well below the river's expected crest. The river was projected to crest at Canton Thursday at nearly 14 feet above flood stage.

Even if population hubs are spared, some fear entire communities may be lost forever, possibly wiping off the map names such as Columbus Junction, Fredonia, Palo and New Hartford.

About 70 percent of Iowa towns have populations of less than 1,000. Just over half of those places have fewer than 500 inhabitants.

Elsewhere in the state, parts of downtown Burlington remained flooded Wednesday, but sandbagging efforts had stopped and officials said they were confident levees would hold. The Great River Bridge at Burlington was still closed due to high water.

In Cedar Rapids, officials allowed more people into damaged homes and businesses. Residents were being urged to conserve water because the water system had only half its normal supply.

South of Iowa City, the town of Columbus Junction, population 2,000, suffered a major blow because it's below the confluence of the Iowa and Cedars rivers. The medical center, pharmacy, day-care, senior center, a hotel and a dozen other businesses were under about 10 feet of water after a levee broke Saturday.

Connie Lewis, 78, who has lived in Columbus Junction for 40 years, often wondered who would keep the town going when her generation passed. When she saw droves of young people filling sandbags and vacuuming the United Methodist Church so it could be used for a shelter, she got her answer.

"And now we know we are going to be OK," she says. "It was such a good cementing experience. Children of all colors were helping. You find out when you need them, they step up to the plate."

These are places where people have learned to lean on each other instead of waiting for outside help.

Oakville sits at the bottom of a hairpin turn the Iowa River makes on its course to the Mississippi. When it became clear the levee would fail, trucking company owners Trina and Ward Gabeline scrambled to help friends save whatever they could.

They gathered about three dozen truck trailers and dropped them off at houses so families could load them with furniture and heirlooms. Then the company retrieved them and carried the cargo to higher ground.

"We didn't do it expecting to get paid," Trina Gabeline said, her blue eyes bloodshot from crying. "We did it to help the people. Because these things that are in these trailers, that's the only thing these people have left right now."

Meanwhile, Gabeline's three brothers helped shore up levees. One was filling trucks with sand, another hauled the sand to bagging stations and a third used an all-terrain vehicle to take finished sandbags to the flood walls.

Troy Massner, who lives on a bluff above Oakville, took the day off from his job as a systems manager for Wal-Mart to help friends. He spent much of Monday wading through putrid water retrieving propane tanks that had floated loose from submerged hog farms.

The day of the flood, local excavating company owner Jon Fye braved the strong currents to rescue a grain elevator worker who became trapped at the TriOak plant. When river levels had stabilized, he went back with Gabeline to inspect the damage.

Fye steered the small boat gingerly around submerged cars and past a picturesque Victorian house where an American flag hung limply from the porch into muddy waters that reeked of diesel fuel and hog waste.

Gabeline stared at house after house flooded to the eaves and ticked off the names of the families who had lived there: "Hayes, Yotters, Kronfeldts, Beedings, Reids, Browns. There's numerous Kuntzes and Lanzes along here."

Fye said people in many small towns have already learned to live without comforts city folks take for granted.

"The small town suffers with no grocery stores anymore, hardly any gas stations," said Fye, who lives in the even smaller nearby town of Sperry.

Fye said wealthier farmers should bounce back from the disaster fairly quickly. But for many friends and neighbors already living on the edge, the floods could spell doom.

"For some it's a bad year, a terrible year," he said as he cleared corn stalks from the propeller of his boat. "But for some, it's the end."