Slow moving thunderstorms caused river water to breech their banks, and the deadly Big Thompson Flood raced through the canyon. The storm dumped nearly twelve inches of rain in a four to six hour, proving to be too much for the riverbanks.
A 25 foot wall of water rushed down Big Thompson Canyon. Many people escaped the floods by car, and hastily phoned loved ones of the coming danger, but in many cases it was too late.
The Big Thompson Flood claimed the lives of 144 victims. More than 800 people were rescued by helicopter, and hundreds of homes and businesses were lost to the raging waters.
Monday, in Loveland, a high-water marker was unveiled marking the 30 year anniversary of the flood.