Since the region’s worst flooding in decades began Wednesday four people have already been confirmed dead and police expects to find more bodies as the scope of damage becomes clear.
“Given the destruction, there is a high probability” of more fatalities, Boulder County Sheriff Joe Pelle said at a media briefing.
However, authorities said some of those 584 residents who remain unaccounted for might be stranded or cut off from electricity and communication.
The flood zone has grown to cover an area of nearly 11,655 square kilometres (4,500 square miles). Flash flood waters toppled buildings, washed out roads and bridges effectively cutting ground access to the area.
Search-and-rescue teams deployed to the area are using boats and helicopters to pull stranded residents to safety. By Saturday evening, more than 1,200 people had been evacuated, National Guard Lt. Col. Mitch Utterback said.
The scope of the damage dealt to infrastructure and property remains unknown, as assessment teams are expected to begin evaluation once the water recedes. The National Weather Service warned of scattered showers and thunderstorms later on Saturday and into Sunday that could possibly trigger more flash flooding.