More than 1,200 people have been rescued in the wake of the flood that's left at least six people dead and hundreds unaccounted for in Colorado, officials there say.
The rescues are part of what National Guard Lt. Col. Mitch Utterback says is the largest aerial rescue operation since Hurricane Katrina in 2005. According to the Boulder County Sheriff's Office, about 700 people were evacuated via air.
"It's been an amazing day," Boulder Sheriff Joe Pelle said at a news conference late Saturday. "An amazing 24 hours of saving lives."
About 200 people were airlifted from Jamestown, Colo., to Boulder Municipal Airport, Pelle said.
Other rescues were conducted by land. Roughly 500 people were driven out of Lyons, Colo., but impassable roads in other parts of the state forced rescue officials to dispatch helicopters. The Wyoming National Guard sent five Black Hawk helicopters and 20 crew members to Colorado to assist in the evacuations.
Still, news of the successful rescue effort was tempered by uncertainty.
More than 230 people remained unaccounted for in Boulder County and another 482 in Larimer County, officials said Sunday, cautioning that the death toll could rise as the floodwaters recede.
"There might be further loss of life," Pelle said. "It's certainly a high probability."
But officials were also optimistic that some of those unaccounted were counted twice, or were safe but unable to communicate with family members.
The Denver Post reported Wiyanna Nelson and Wesley Quinlan, a 19-year-old couple, were driving west of Boulder when their car became stuck in the raging floodwaters.
Two additional victims whose homes were swept away were also feared dead, sheriff's spokesman John Schulz said Sunday, bringing the death toll to six.
An 80-year-old woman "was injured and couldn't get out of her house, and when neighbors went back to help her, the house was gone," Schulz said. A 60-year-old woman who lived in the same area likely died in the flood, too.
More than 4,000 residents along Boulder Creek were ordered evacuated as Boulder remains under a flash flood watch through Sunday afternoon. Heavy rains are forecast through at least midday, hampering the air rescue effort.
"Ground rescues will continue today even if the helicopters can't fly," Boulder Police public information officer Kim Kobel tweeted.
Meanwhile, officials warn that while the weather conditions may improve later Sunday, the situation remains dangerous.
According to University of Colorado police spokesman Ryan Huff, one student was stopped from tubing on Boulder Creek.
"This is not the time to be playing around," Huff told the Daily Camera. "This continues to be a dangerous situation."