(NECN) - Flash flooding has left three people dead in Colorado.
Heavy rain sent walls of water crashing down mountainsides overnight.
Flooding has been reported from Colorado Springs to north of Fort Collins.
Some mountain communities have been left isolated as a result.
The flooding has also forced people from their homes and caused road collapses.
Search and rescue teams are having trouble reaching stranded residents and motorists in some areas.
“All the preparation in the world, all the want to in the world can't put people up those canyons while those walls of water and debris are coming down,” said Sheriff Joe Pelle.
Classes have also been canceled at the University of Colorado in Boulder.
Recent wildfires have only made the situation worse for people across the state because the scorched soil absorbs less water.