The torrent of water from heavy rainfall spawned by last week's "bomb cyclone" and snowmelt has led to devastating flooding across several Midwestern states, including swamping a major Air Force base in Nebraska that's key to the nation’s nuclear attack response.

About one-third of Offutt Air Force Base -- including offices, hangars and nearly 3,000 feet of the base's 11,700-foot runway -- is underwater due to flooding from the Missouri River south of Omaha.

Spokeswoman Tech. Sgt. Rachelle Blake told the Omaha World-Herald that 60 buildings, mostly on the south end of the base, have been damaged, including about 30 that were completely inundated with as much as 8 feet of water.

Airmen from the 55th Wing had been filling thousands of sandbags in a round-the-clock effort to fortify facilities but were forced to give up after filling 235,000 sandbags and preparing 460 flood barriers.

“It was a lost cause," Blake told the World-Herald. "We gave up."

MIDWEST BRACING FOR MORE 'UNPRECEDENTED' FLOODING THAT HAS SHATTERED RECORD-HIGH RIVER LEVELS

Col. Michael Manion, commander of the 55th Wing, has been providing updates on the flooding on Facebook. As of Tuesday morning, he reported there has been "slow water regression" that's allowed some high points that were underwater to be revealed. Disaster recovery crews are expected to arrive by the end of the week to begin work when floodwaters fully recede.

"The wheels are in motion but remember - it will likely take months and months and the SE side of the base will never look the same," he wrote.

Nine aircraft of the 33 reconnaissance jets based at the facility were able to be flown out before the runway was flooded, according to Manion.

One of the planes was a Boeing-made E4-B plane, which is meant to serve as an aerial command center in case of national emergency or destruction of ground bases in an event such as a nuclear attack, Reuters reported.

The base is also the location of the U.S. Strategic Command, which oversees the country’s nuclear arsenal. The Strategic Command headquarters is set on a hill and was not affected by the floods, and neither was its new $1.3 billion building.

Many of the senior leaders from STRATCOM are participating in a worldwide military exercise called Global Lightning, which began Wednesday, according to the World-Herald.

MIDWEST FLOODS DEVASTATE NEBRASKA CITY, LEAVING MANY WITHOUT HOMES

Satellite photos released on Monday by NASA show the extent of the flooding in Nebraska, particularly along the Platte, Missouri and Elkhorn Rivers.

The effect of the flooding can particularly be seen around Offutt Air Force base.

"Several communities west of Omaha (between the Elkhorn and Platte Rivers) either flooded or temporarily became islands as floodwaters encroached from both sides," NASA Earth posted to Facebook.

The agency said that a "rare confluence of circumstances" has contributed to the late-winter flood.

"Extreme cold earlier in the winter set the stage by preserving a significant amount of snow; it also created a thick layer of ice on waterways and made the ground less permeable than usual," NASA said. "When an intense storm brought downpours and unusually warm air to the region in March, it rapidly melted much of the snow and ice, producing enormous runoff in a short period."

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At least 3 deaths were blamed on flooding, and two other men have been missing for days.

While river depths were starting to level off in parts of Nebraska on Sunday, the water is so high in many places that serious flooding is expected to remain for several days. And downstream communities in Kansas and Missouri were bracing for likely flooding.

The rising Mississippi River also was creating concern. The Mississippi was already at major flood level along the Iowa-Illinois border, closing roads and highways and swamping thousands of acres of farmland. Moderate Mississippi River flooding was expected at several Missouri cities, including St. Louis.

The Associated Press contributed to this report.