Authorities were using boats and large vehicles on Saturday to rescue and evacuate residents in parts of the Midwest where a recent deluge of rainwater and snowmelt was sent pouring over frozen ground, overwhelming creeks and rivers, and killing at least one person.

Rescue efforts in eastern Nebraska were hampered by reports of levee breaches and washouts of bridges and roads, including part of Nebraska Highway 92, leading in and out of southwest Omaha. Authorities confirmed that a bridge on that highway that crosses the Elkhorn River had been washed out Saturday.

And in Freemont, west of Omaha, the Dodge County Sheriff’s Office issued a mandatory evacuation for some residents after floodwaters broke through a levee along the Platte River.

The flooding followed days of snow and rain — record-setting, in some places — that swept through the West and Midwest.

The deluge pushed some waterways to record levels in Nebraska, South Dakota, Iowa and Minnesota. The flooding was the worst in nearly a decade in places.

The family of farmer James Wilke, 50, of Columbus, Nebraska, said he was killed Thursday when a bridge collapsed as he was using his tractor to try to reach stranded motorists on Thursday. His body was found downstream, his cousin Paul Wilke told the Columbus Telegram. Gass Haney Funeral Home confirmed James Wilke’s death.

At least two other people were missing in floodwaters in Nebraska. Officials said a Norfolk man was seen on top of his flooded car late Thursday before being swept away in the water and another man was swept away by waters when a dam collapsed on the Niobrara River.

Officials in Sarpy County, south of Omaha, said Saturday that power may be shut off to communities along the Missouri, Platte and Elkhorn rivers for safety reasons. They warned those who choose to ignore calls to evacuate that rescues would be attempted only during daylight hours.

Some cities and towns, such as North Bend on the banks of the Platte River, were submerged. Others, such as Waterloo and Freemont, were surrounded by floodwaters, stranding residents in virtual islands with no access in or out.

Farther east, the Mississippi River saw moderate flooding in Illinois from Rock Island south to Gladstone. Meteorologist Brian Pierce with the National Weather Service’s Quad Cities office in Davenport, Iowa, said flooding on the Mississippi could get worse a few weeks as more snow melts in Minnesota and Wisconsin.

“What we’re having now is the dress rehearsal for the main event that’s going to happen in early April,” he said of the flooding on the Mississippi.

Rising waters along the Pecatonica and Rock rivers flooded some homes in the northern Illinois cities of Freeport, Rockford and Machesney Park.

The National Weather Service said record crests were possible along the rivers, with water levels forecast to continue to rise over the next several days and remain above flood stage through most of the weekend.