In Colorado at least three people are dead, streets are flooded, and mountain towns are isolated after days of heavy rain caused flash flooding that is expected to continue through Friday.

"In Boulder, the rainfall record for September set in 1940 was shattered," Keith Coffman of Reuters reports.

Surging Boulder Creek floodwaters, coming from Boulder Canyon above the city, are now running through its heart.

"There's so much water coming out of the canyon, it has to go somewhere, and unfortunately it's coming into the city," Ashlee Herring, spokeswoman for the Boulder office of Emergency Management, told Reuters.

The torrent triggered the evacuation of some 4,000 residents late on Thursday. On Friday the National Guard began evacuating at least 500 people from Lyons, north of Denver, after the town was cut off by rising floodwaters.

"There's no way out of town. There's no way into town. So, basically, now we're just on an island," Jason Stillman, 37, who was forced to evacuate his home in Lyons at about 3 a.m., told The Weather Channel.

It's clear why some people are stranded: A home and car are stranded after a flash flood in Coal Creek destroyed the bridge near Golden, Colo. Sept. 12, 2013. REUTERS/Rick Wilking

The Colorado resident who took the following pictures told Business Insider: "It's so crazy here — just about every other street is closed and there are rocks and trees everywhere." As you can see, the water is starting to reach underneath homes. And into homes. The caption for the photo below reads: "If anyone is free to help tomorrow. A friend of mine could use some. This is his living room."

Here's a video:

"In Boulder we don't have streets but creeks"

Neighbors survey a dike created to funnel water down 7th Street as heavy rains cause severe flooding in Boulder, Colo. Sept. 12, 2013. REUTERS/Mark Leffingwell

One more perspective: