Denver, Colorado wildfires burn hundreds of homes, force thousands to evacuate

An estimated 580 homes, a hotel and a shopping centre have burned and tens of thousands of people have been evacuated in wind-fuelled wildfires outside Denver, officials said today.

At least one first responder and six others were injured, though Boulder County Sheriff Joe Pelle acknowledged there could be more injuries and deaths could be possible because of the intensity of fires that quickly swept across the region as winds gusted up to almost 170km/h).

The first fire erupted just before 10.30am and was "attacked pretty quickly and laid down later in the day and is currently being monitored" with no structures lost, Pelle said.

A second wildfire, reported just after 11am, "ballooned and spread rapidly east," Pelle said. The blaze spans 6.5sq km and has engulfed parts of the area in smoky, orangish skies and sent residents scrambling to get to safety.

The activity of the fires, which are burning unusually late into the winter season, will depend on how the winds behave overnight and could determine when crews are able to go in and begin assessing the damage and searching for any victims.

"This is the kind of fire we can't fight head on," Pelle said. "We actually had deputy sheriffs and firefighters in areas that had to pull out because they just got overrun," he added.

Evacuations have been ordered for the city of Louisville, home to about 21,000 people, and Superior, which has another 13,000 residents.

The neighbouring towns are about 32km northwest of Denver in an area filled with middle and upper-middle class subdivisions surrounded by shopping centers, parks and schools. The area is in between Denver and Boulder, a foothills college town home to the University of Colorado.

Firefighters spray water on a structure as a wildfire burns. Thousands of residents in Superior and Louisville, two communities near Denver, were ordered to evacuate. Photo / AP

Residents evacuated fairly calmly and orderly, but the winding streets in the suburban subdivisions quickly became clogged as people tried to get out. It sometimes took cars as long as 45 minutes to advance less than a kilometre.

Small fires cropped up here and there in surprising places — on the grass in a median or in a dumpster in the middle of a parking lot — as wind gusts caused the fire to jump and spread. Shifting winds caused the skies to turn from clear to smoky and then back again as emergency sirens blared nearby.

Some of the several blazes in the area were sparked by downed power lines.

Six people who were injured in the fires were being treated at UCHealth Broomfield Hospital, spokesperson Kelli Christensen said. A nearby portion of US Highway 36 was shut down.

Colorado's Front Range, where most of the state's population lives, had an extremely dry and mild fall, and winter so far has continued to be mostly dry. Denver set a record for most consecutive days without snow before it got a small storm on December 10. It hasn't snowed since, though snow is expected in the region tomorrow.

Law enforcement personnel guide motorists away from the Flatiron Crossing mall as a wildfire burns near the shopping centre. Photo / AP

One video captured by a bystander outside a Superior Costco store showed an apocalyptic scene with winds whipping through barren trees in the parking lot surrounded by gray skies, a hazy sun and small fires scattered across the ground.

Leah Angstman and her husband saw similar dark skies while returning to their Louisville home from Denver International Airport after being away for the holidays. As they were sitting on the bus going toward Boulder, Angstman recalled instantly leaving clear blue skies and entering clouds of brown and yellow smoke.

"The wind rocked the bus so hard that I thought the bus would tip," she wrote in a message to The Associated Press.

The visibility was so poor that the bus had to pull over and they waited a half-hour until a regional transit authority van escorted them to a turnaround on the highway. There she saw four separate fires burning in bushes across the freeway, she said.

"The sky was dark, dark brown, and the dirt was blowing in swirls across the sidewalk like snakes," she said.

Angstman later ended up evacuating, getting in a car with her husband and driving northeast without knowing where they would end up.

Vignesh Kasinath, an assistant professor of biochemistry at the University of Colorado in Boulder, evacuated from a neighbourhood in Superior with his wife and her parents.
Kasinath said the family was overwhelmed because of the sudden evacuation warning and anxious from the chaos while trying to leave.

Tens of thousands of people have been evacuated in wind-fuelled wildfires outside Denver. Photo / AP

"It's only because I am active on Twitter I came to know about this," said Kasinath, who said he did not receive an official evacuation notice from authorities.

The fires prompted Governor Jared Polis to declare a state of a emergency, allowing the state to access disaster emergency funds.

The evacuations come as climate change is making weather more extreme and wildfires more frequent and destructive, scientists say. A historic drought and heat waves have made wildfires harder to fight in the US West.

Ninety per cent of Boulder County is in severe or extreme drought, and hasn't seen substantial rainfall since mid-summer.

"With any snow on the ground, this absolutely would not have happened in the way that it did," said snow hydrologist Keith Musselman, who was at home when the fire broke out not far away.

Musselman said severe fire risk was expected in September and October after a dry summer, but the lack of any precipitation – snow or rain – this late in the season was highly unusual.

The National Weather Service predicted up to a foot of snow could fall tomorrow in Boulder, and that moisture would bring substantial relief, Musselman said. - AP