Water began flowing under the 4-foot-high barrier around 4:30 a.m. An alarm sounded and the few residents remaining in the flood plain were ordered to get out.
"It was a valiant effort," said Chris Azar of the Winfield-Foley Fire Department. "It's unfortunate that we couldn't do more but Mother Nature won. Now, just give it time for the water to recede."
On Friday, the Pin Oak levee that protected part of the town of 720 residents gave way, and within hours the National Guard began constructing the makeshift levee around a cluster of about 100 homes. That new levee had a steel frame with layers of dirt, plastic and sandbags. Hundreds of volunteers had filled sandbags for the effort.
The new barrier appeared to be holding well, until Saturday morning.
Azar said at least 60 homes in the cluster were flooded, although authorities were still assessing the damage. Evacuees are mostly staying with relatives or friends, though a few were staying at a Red Cross shelter set up at the high school.
Many other homes in Winfield sit on a hill above the river and are well out of harm's way.
Winfield, 45 miles northwest of St. Louis, is in Lincoln County, which has been particularly hard hit by flooding caused by torrential rain that fell across the Midwest in early June.
County emergency operations spokesman Andy Binder said 92 homes have been destroyed, 36 others have major damage and 650 can't be evaluated yet because they remain inaccessible.
In nearby Foley, the mayor requested that anyone who doesn't live there stay out of town. The wake caused by vehicles driving through floodwaters was causing more problems for already damaged homes.
The Mississippi is receding at Winfield and towns to the north, but remains well above flood stage. Crests will reach St. Louis on Monday and Cape Girardeau in southeast Missouri on Wednesday.
Cape Girardeau is expected to see a crest of 43 feet. At that level, some residents will have to evacuate and 100,000 acres of farmland will be flooded, the National Weather Service said.
Elsewhere in the state, heavy rain drenched much of southwest Missouri early Saturday, causing widespread flooding of low-lying areas and roads.
Up to 5 inches of rain fell in two hours in Taney County, where a bridge along Lake Taneycomo collapsed and emergency workers had to evacuate around 15 people from a flooded mobile home park, said Chris Berndt, the county's emergency management director. He said no one was hurt in the bridge collapse.
Across the central part of the state, the Missouri River, which joins the Mississippi near St. Louis, is rising because of heavy rain that fell on Thursday and early Friday. The National Weather Service predicts moderate flooding in parts of mid-Missouri by Monday.
At Jefferson City, the state capital in the middle of the state, the Missouri River is expected to close some roads and flood about 300 acres of farmland, the weather service said.
While Winfield lost the battle to save its levee, some Missouri towns have apparently weathered the threat.
The levee held at Alexandria, a tiny town near the Iowa state line, and water is receding, allowing evacuees to move back home. A few houses had water inside, but nothing irreparable.
A massive sandbagging effort was still protecting most of the businesses in Clarksville, and water was still high but receding in nearby Louisiana. Both of those towns don't have levees.