Colorado has been hit with some disastrous flooding that devastated several areas including Boulder. The Denver Post reported this morning that the historic floods have killed at least six people, but the truly terrifying figure is the state’s 1,253 missing persons who are unaccounted for, many of whom are presumed dead.

FEMA deployed two Incident Management Assistance Teams with accompanying staff to assist Colorado emergency centers, and three federal search-and-rescue teams are reported to already searching for those missing with an additional two search teams expected to join them later today.

The worst of the flooding started last Wednesday along the South Platte River and moved downstream to the northeastern part of Colorado. FEMA has reported 17,494 homes damaged by flooding with 1,502 houses destroyed and 11,700 evacuees from the disaster zone. The disaster relief organization also provided 22,000 meals and over 65,000 liters of drinking water.

A White House statement released yesterday said President Obama has officially declared the area a disaster zone, and talked to Colorado Governor John Hickenlooper for updates on the situation. During the conversation, Obama reiterated his desire to provide whatever aid necessary to ameliorate the disaster.

Meanwhile, LiveScience reported that the University of Colorado’s Natural Hazards Center had listed a Boulder flash flood as one of several “disasters waiting to happen” on a report in 2004, and the U.S. Geological Survey has mapped the ancient remains of flash floods that occurred thousands of years ago along the Colorado Front Range.

After the 1976 Big Thompson Canyon flood that drowned 145 people, Colorado officials bought undeveloped land along the flood zones to prevent development, and the city’s bike paths also served as floodwater channels with breakaway fences that prevented debris from clogging a flood’s path.

Matt Klesch, a hydrometeorologist for the University Corporation for Academic Research based in Boulder, said that “We knew this kind of rain was possible [and] Big Thompson Canyon was a wake-up moment. Prior to that, we weren’t really prepared.”

Referring to the 2013 flooding, Klesch said that the relief effort was “pretty well prepared for it, but it doesn’t mean all the residents were well prepared for it… Part of emergency management preparations is knowing a certain percentage of people are going to make bad decisions.”

The Denver Post collected a series of stories about the flood, both sad and heroic, that you can read here at the end of their article.

[Image via this AP YouTube video of footage and images from the flooding]