Thousands evacuated in Colorado flooding

Watch: The state of Colorado is in the grips of powerful and deadly flash flooding. Eric Sorensen reports. 

LYONS, Colo. – Thousands more people in Colorado were ordered to evacuate as water rose to dangerous levels amid a storm system that has been dropping rain for a week.

Rescuers struggled to reach dozens of people cut off by flooding in mountain communities.

At least three people were killed.

Boulder County spokesman James Burrus said 17 people were unaccounted for Friday.

“Unaccounted for doesn’t mean missing. It means we haven’t heard back from them,” he said.

Two backpackers were said to be missing as well after they were hiking in the mountains and the changing weather caught them by surprise, a family member said.

READ MORE: Incredible video from Colorado floods

Late Thursday night, Boulder city officials said they sent a notice to head to higher ground to about 4,000 people living along Boulder Creek around the mouth of Boulder Canyon after 11 p.m. MDT, according to a report in Boulder’s Daily Camera newspaper.

Boulder County spokesman James Burrus told The Associated Press that about 8,000 telephone numbers with the message to evacuate were called, but officials aren’t sure how many individuals that represented.

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.

Video: Colorado Gov. John Hickenlooper holds a news conference to talk about the flooding in his state

“There’s no way out of town. There’s no way into town. So, basically, now we’re just on an island,” said Jason Stillman, 37, who was forced with his fiancee to evacuate their home after a nearby river began to overflow into the street.

One person was killed when a structure collapsed. Another man drowned in flood waters, and a woman who was with him was missing after swept away when the vehicle she was riding in got stuck.

The man died after getting out of the vehicle to help her, Commander Heidi Prentup of the Boulder Sheriff’s Office said.

Elsewhere, Colorado Springs police conducting flood patrols found the body of a man.

Some of the flooding was exacerbated by wildfire “burn scars” that have spawned flash floods all summer in the mountains. The flames strip away vegetation that normally helps absorbs excess water and leave a residue behind that sheds water.