Flames explode as wildfires burned near a small shopping center Thursday, Dec. 30, 2021, near Broomfield, Colo. Homes surrounding the Flatiron Crossing mall were being evacuated as wildfires raced through the grasslands as high winds raked the intermountain West. (AP Photo/David Zalubowski)

DENVER — An estimated 580 homes, a hotel and a shopping center have burned and tens of thousands of people were evacuated in wind-fueled wildfires outside Denver, officials said Thursday evening.

Boulder County Sheriff Joe Pelle said only one injury has been reported, but didn't rule out finding out later about more severe injuries or death due to the intensity of fires that quickly swept across the region as winds gusted up to 105 mph.

The first fire erupted just before 10:30 a.m. 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 11 a.m., “ballooned and spread rapidly east,” Pelle said. The blaze spans 2.5 square miles and has engulfed parts of the area in smoky, orangish skies and sent residents scrambling to get to safety.

Tonight's wind activity will 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.

The city of Louisville, which has a population of about 21,000, was ordered to evacuate after residents in Superior, which has 13,000 residents, were told to leave. The neighboring towns are roughly 20 miles northwest of Denver.

Several blazes started in the area Thursday, at least some 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 U.S. Highway 36 also 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. Snow was expected Friday in the region though.The fires prompted Gov. Jared Polis to declare a state of a emergency, allowing the state to access disaster emergency funds.

A firefighter walks up a road near a home at Middle Fork Road and Foothills Highway north of Boulder, Colo., Thursday. Homes, a hotel and a shopping center have burned and tens of thousands of people were evacuated in wind-fueled wildfires outside Denver, officials said Thursday evening.

Firefighters spray water on a structure fire as a wildfire burns, Thursday, Dec. 30, 2021, in Superior, Colo. Thousands of residents in Superior and Louisville, two communities near Denver, were ordered to evacuate Thursday because of a wind-fueled wildfire that engulfed parts of the area in smoky, orangish skies.