Cracks forming in an earthen levee holding back the swelling Red River reportedly have prompted officials to order the evacuation of a Fargo, N.D., neighborhood and a nursing home.
Mayor Dennis Walaker said residents were not in immediate danger and water was not flowing over the levee, the Associated Press reported, but officers were going door-to-door in the River Vili neighborood to order out residents of about 40 houses and the Riverview Estates nursing home.
The new threat emerged as the river headed toward an unprecedented crest that was sending Fargo-area residents into "uncharted territory," Walaker said today.
Officials predicted the Red River could crest as high as 43 feet this weekend -- two feet higher than forecasters had previously said.
"No one has ever seen the river at this level in the city of Fargo since the beginning of history," Walaker said. "We need all the help we can get."
Volunteers scrambled to try to add one more foot of sandbags around the river while the city put final touches on an evacuation plan. The rising river waters forced city officials to call on thousands of additional volunteers Thursday in a race to raise the levees to 43 feet.
"To raise a whole foot is a monumental event," requiring millions of sandbags, a volunteer told ABC News.
The Red River, which divides North Dakota and Minnesota, stood at 39 feet this afternoon. The National Weather Service, which had predicted a crest of 41 feet by Saturday, said the waters could now reach 43 feet.
"I hope we're not doing this all for nothing," said Donna Decker, who was packing sandbags in Fargo's indoor stadium. "I just hope it works."
Scattered evacuations were reported south of the city, where Coast Guard air boats plucked residents George and Dorothy Sealy from their flooded home.
"I said, 'I'm not leaving.' I don't care, but overnight the basement took on water," Dorothy Sealy said from a stretcher.
Nursing homes in the city began to evacuate patients in an attempt to bring the most vulnerable to higher ground. North Dakota's largest city released evacuation plans late Thursday for its 92,000 residents.
"If you know you need to get out, we need you to get out today," Cass County Sheriff Paul Laney told residents, warming of the conditions expected to arrive.
Wild spring weather continues to pummel various regions of the country. In Mississippi, Gov. Haley Barbour declared a state of emergency after an overnight tornado injured 20 people and damaged at least 60 homes.
But it's North Dakota's ominous weekend forecast that could be the most devastating.
The worst of it is playing out in Fargo, where volunteers have thrown their hearts and hopes into constructing huge sandbag levees along a 12-mile stretch of river ahead of expected floods.
Tim Hogan and his nephew Jesse drove three hours to help.
"We've been working for two-and-a-half days and you really think you're doing something," Hogan told ABC News.
The National Weather Service predicted that the river could crest at as high as 43 feet by Saturday afternoon, far exceeding estimates and record levels set during the devastating floods of 1997.