Three people have died in floods in and around Boulder, Colo., and thousands have been forced to seek shelter or told to evacuate since heavy rain intensified earlier this week. The floodwaters isolated the towns of Lyons and Jamestown on Thursday, the Denver Post reported:

At 2:20 a.m., over the emergency broadcast system at Lyons High School, a voice warned of flash flooding on the St. Vrain. Sirens blared. Residents knocked on doors, hurriedly packed, hoped for the best.

In Jamestown, deeper in the mountains of Boulder County, emergency notification calls stirred residents awake at 2:17 a.m. Water and boulders roared down Little Jim Creek. The one-room elementary schoolhouse became a shelter. A man was presumed dead after a single-story yellow house collapsed.

The 100-year flood — or was 500 years more like it? — had come.

Within hours, both towns were islands. A deluge even the National Weather Service described as bearing biblical proportions had swallowed highways and roads into Jamestown and Lyons . . .

“We have been preparing for this 100-year flood, which is so overdue,” said Mary Huron Hunter, whose 110-year-old house in Lyons is two or three blocks from the water’s reach. “And here we are.”

Rain continued to fall Thursday night in both communities; both Lyons and Jamestown remained under flash-flood warnings.

Bonnie-Sue Hitchcock, her boyfriend and her 16-year-old daughter left their home two blocks from South St. Vrain Creek in Lyons after their across-the-street neighbor banged on the door at 2 a.m.

Hitchcock wore blue striped pajamas. She was on crutches from a recent hip surgery. She left with a computer, an overnight bag and a 16-year-old border collie that grew up on a fishing boat in Alaska.

On Thursday afternoon, from the vantage point of a friend’s house on higher ground bordering open space, Hitchcock could peer through the trees to see her house had suffered, at the least, serious damage.

A trailer park two blocks away appeared completely lost, she said. Powers lines were down.

The Denver Post

Other areas were also endangered, according to the Associated Press:

Late Thursday, warning sirens blared in Boulder and city officials sent notice to about 4,000 people living along Boulder Creek around the mouth of Boulder Canyon to head for higher ground, according to Boulder’s Daily Camera newspaper.

The alert was prompted by rapidly rising creek levels caused by water backing up at the mouth of the canyon because of debris and mud coming off the mountainsides, the city Office of Emergency Management said.

The creek began to recede after midnight, but the conditions remained dangerous and a surprising amount of water was still flowing into the city’s streets, Police Chief Mark Beckner told the Daily Camera after touring the damage.

The entire hamlet of Eldorado Springs, about 500 people, was urged to evacuate because of a flash flood and mudslide threat along South Boulder Creek, Burrus said.

Northwest of Boulder, the overflowing Vrain Creek cut the town of Longmont in half. Evacuation requests were issued for some neighborhoods, all major roads were closed, and several thousand homes and businesses were without power, he said.

Interstate 25 east of Loveland was closed in both directions Friday, state transportation officials said.

In Fort Collins, neighborhoods along the Cache La Poudre River were evacuated overnight, with the river expected to rise to nearly 2 feet above flood stage Friday morning, according to the National Weather Service.

Associated Press

For more information, including official phone numbers and locations of shelters in the area, see this map from Google Crisis Response.

Officials in Boulder, Colo., say they've told about 4,000 people living around the mouth of Boulder Canyon to evacuate. (Associated Press)