BOULDER, United States, Sept. 14 (Xinhua) -- A massive rescue operation unfolded Saturday in northeastern Colorado, as the National Guard and local crews raced to evacuate thousands of people stranded by epic flooding.
"We have literally thousands of people in the county stranded now, waiting for help," said Larimer County spokesman John Schulz late Saturday.
More than 1,000 stranded residents have been evacuated from flooded areas by nightfall Saturday, according to the authorities.
In addition to the four fatalities that have been confirmed since the floods began Wednesday, a 60-year-old woman was presumed dead Saturday after she was seen swept away by surging waters along with her house.
Additional deaths are feared as hundreds of people remain unaccounted for.
"We assume there will be further loss of life," said Sheriff Joe Pelle of Boulder city, where the historic towns of Lyons and Jamestown have been devastated.
The National Weather Service predicted more heavy rain late Saturday and all day Sunday in northeastern Colorado.
The flooding is historic in coverage, with floodwaters from five days of heavy rain rushing down from mountain cliffs and canyons into the flat foothills and plains, said Schulz, the Larimer County spokesman.
"The biggest problem is that the flood is so extensive," he said. The affected area is now more than 11,000 square km, comparable to the size of Connecticut state.
Colorado Governor John Hickenlooper has declared a disaster emergency for 14 counties, and authorized 6 million dollars of fund to be used for flood response and recovery.
The National Guard urged thousands of people without electricity to evacuate while they have the chance, because "it might take weeks" to restore power.
Meanwhile, police said they have increased patrols to counter possible lootings.
The floods are considered to be the worst in the state since 1976, when nearly 150 people died in Larimer County in a flash flood along the Big Thompson Canyon.