Courtesy NBC News

By Alexander Smith and Matthew DeLuca, NBC News

Torrential rain drenched parts of Colorado, washing away homes and causing at least two deaths as officials worked Thursday to evacuate towns and keep people out of the path of the rising water.

The National Weather Service described a "life-threatening situation" in an emergency message issued just after midnight local time for several areas around Boulder, where about 6.5 inches of rain fell in the last 24 hours, according to the National Weather Service.

The first death was reported near Jamestown, according to officials, and was thought to be because of a building collapse. The Colorado Springs Fire Department reported a second death on Thursday morning after a body was recovered near Interstate 25.

Authorities found the second body while out patrolling in the I-25 area around 5:30 a.m. local time, Colorado Springs Fire Department spokeswoman Sunny Smaldino told NBC News affiliate KUSA.

The deadliest flood in Colorado history occurred in Larimer County in July of 1976, when the Big Thompson River swelled its banks, killing 144 people and causing more than $85 million in damages, according to data compiled by the University Corporation for Atmospheric Research.

Water reached as high as first-floor windows in some parts of Boulder, a police and fire spokeswoman said. Dive teams were dispatched after cars were seen floating.

"There was one woman that was on top of a vehicle and the vehicle was actually on its side," the spokeswoman said. The rain has also caused mudslides 2 to 3 feet deep in some areas, which are impassable "even if you have an SUV," she added.

Libraries, recreation centers and other Boulder facilities were closed, according to the city's office of emergency management. Energy companies workers were trying to restore power after several flood-related outages, but expected more problems to be reported as the sun rose, according to the emergency office's website.

More than 700 customers were without power on Thursday morning in and around the city of Boulder, according to an outage map maintained by utility supplier Xcel Energy.

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