Enlarge By Allen Fredrickson, Reuters Volunteers pass sandbags to add a foot on top of a permanent earthen dike on the southside of Fargo, N.D., which protects the city from flooding on the Red River, March 27.  VIDEO: FARGO FLOOD RISING ABOVE PREDECESSORS  ABOUT FLOODS Resources: More information about floods National Weather Service: National river flood outlook National Weather Service: National current river observations Graphic: Why floods are so dangerous Graphic: How rain, snowmelt spawn floods Graphic: Floods arrive on storm train

But city leaders offered a ray of hope to the week-old fight against the rising river: The river flow is slowing and may crest at just 41.5 feet by Saturday.

The National Weather Service had predicted the crest to be as high as 43 feet, scrambling workers and volunteers to extend temporary dikes.

Cold weather — with temperatures dropping below 10 degrees overnight — helped slow the river's flow, Mayor Dennis Walaker said.

"We're pretty confident right now of the river stopping at about 41.5 feet," he said. "We still need the cooperation of everyone who's been assisting us."

He said the city isn't planning on building the city's main 43-foot dike any higher.

"We're not going to proceed to take it to 44. Is that a gamble? We don't think so," Walaker said.

A morning planning meeting between city leaders also drew Gov. John Hoeven and North Dakota Congressmen Earl Pomeroy and Byron Dorgan, as well as representatives of the Army Corps of Engineers, Federal Emergency Management Agency and local and state agencies.

City leaders again scrambled work crews and volunteers to fortify emergency dikes and levees across the city. Fargo public schools will likely remain closed next week because some families were evacuating from vulnerable neighborhoods, officials said.

City officials said they were nearly finished building the emergency dikes and were now moving to the next phase, which is maintaining them and containing any leaks.

Officials asked people to stay off of roads to keep streets clear for sandbag trucks and avoid traffic jams that have been plaguing the area.

The Cass County Sheriff's Department, along with the U.S. Fish and Wildlife Service and Coast Guard, rescued 138 residents from flooded homes the past two days, Sheriff Paul Laney said.

Maj. Gen. David Sprynczynatyk, adjutant general of the North Dakota National Guard, said 1,700 North Dakota and South Dakota troops will be positioned in the city by 5 p.m. to help patrol the city's 28 miles of river, looking for breaches and preparing to shore up levees.

His command has also set up several quick-reaction force teams that would be dispatched to contain any levee leaks, he said. "We will bring in more troops if needed," Sprynczynatyk said.

Officials at MeritCare, Fargo's largest hospital, said they had evacuated 180 long-term patients from the downtown hospital to free up staff to focus on potential emergencies. It was the first time the hospital had done so in its 104-year history.

"This was an incredibly difficult decision," said Bruce Pitts, MeritCare's executive vice president of clinical services. "Our first priority is to provide services to the people of this community."

The cold weather froze sandbags and made it difficult to fortify dikes. But it also slowed the flow of the river, offering a nugget of good news, city commissioner Tim Mahoney said.

"That's the break we needed," Mahoney said.

Authorities in Fargo and across the river in Moorhead, Minn., expanded evacuations Friday across several blocks of their cities. The total number of people ordered from homes wasn't clear.

Just after 2 a.m. Friday, residents in one neighborhood were roused from sleep and ordered to evacuate after authorities found a leak in a dike. The leak left the integrity of the dike in question, police Capt. Tod Dahle said.

"It's not like there's a wall of water going through," he said. "It's just a significant leak."

Fargo spokeswoman Karena Lunday said it was the only overnight breech and crews would start patching it Friday morning.

"We want to go down swinging if we go down," Walaker said.

Several unusual factors sent the Red River surging to historic heights this year. The winter was unusually cold and snowy, which left a large snowpack sitting on top of frozen ground that couldn't absorb it.

Then a warm snap and heavy rain quickly melted the snow and sent it into toward the river.

It all happened to a river that flows north. When most rivers in the United States melt, they send the extra water south toward warmer, open water.

When the Red breaks up, it sends hunks of ice north into colder water that is often still frozen.

Contributing: Associated Press