At least one man is dead, two others are missing and nearly 900 people are inside temporary shelters amid the worst flooding in Nebraska in 50 years following a "bomb cyclone" storm that wreaked havoc across the Great Plains this week.

Nebraska Gov. Pete Ricketts and the the state's national guard on Friday surveyed the damage – including flooded farms, homes, bridges and highways – caused by what Ricketts called "devastating flooding" that's perhaps the worst in a half-century.

"This could last for quite some time,” he said, urging people to "watch the weather and waterways in their communities closely in the coming days, and be prepared for historic levels of flooding even if it has not hit their community yet."

Nebraska has been in a state of emergency since Tuesday due to heavy rainfall. The massive "bomb cyclone" battered the central United States this week with heavy snow, howling winds and several tornadoes. Flooding has forced evacuations in Wisconsin, South Dakota and Minnesota as well.

Stretches of interstates across Nebraska have been shut down. At least four bridges on state highways are washed out and damaged. The Nebraska National Guard on Saturday morning warned residents that it's still dangerous to travel despite the sun that finally appeared.

"We repeat: It is still dangerous to enter any flood waters, and roads continue to be closed across the state," the Nebraska National Guard tweeted. "DO NOT TRAVEL unless necessary, and NEVER drive through flood waters."

The Nebraska Emergency Management Agency has reported emergency declarations in 41 cities and 53 of Nebraska's 93 counties, largely in the northeast part of the state that includes the state's largest city Omaha.

But NEMA set out to dispel reports that a nuclear plant, the Cooper Nuclear Station Facility, near Brownsville, Nebraska, is a threat to flood.

"The photo below is FALSE NEWS — Cooper Nuclear Station Facility is operating at full power," NEMA tweeted. "They have 100% access via an alternate road."

The Omaha-World Herald has reported one fatality, a farmer in the town of Columbus. James Wilke drove his tractor out to assist flood victims despite the howling wind and rain. Two others are believed to be missing.

Wilke tried to cross a bridge, the newspaper reported, but it collapsed because of the tractor's weight, sending Wilkes into a rising creek underneath. His body was discovered around nine hours later near his farm.

"He was always the first to go help somebody,” the newspaper quoted his cousin, Paul Wilke, saying. “He was a person who wouldn’t just talk about making things better. He would do it."

Meanwhile, a levee breech in Fremont, about 50 miles northwest of Omaha, forced evacuations in some parts of the community to seek higher ground.

The Nebraska-SW Iowa Region of the Red Cross has set up several temporary shelters across Nebraska for people to seek refuge. Red Cross has said they've served 880 folks so far.