Tens of thousands of people were evacuated and hundreds of homes were destroyed as wildfires spread near Denver, Colorado.
The fires are moving in Boulder County, located north of Denver, prompting Gov. Jared Polis to declare an emergency.
Boulder County Sheriff Joe Pelle said there could be more injuries and deaths than reported due to the speed and intensity of the fire, known as the Marshall Fire.
“This is the kind of fire we can’t fight head-on,” Pelle told The Associated Press. “We actually had deputy sheriffs and firefighters in areas that had to pull out because they just got overrun.”
Within hours, the blaze had swept an estimated 1,600 acres and destroyed more than 500 homes, Pelle told reporters at a news briefing.
“We know that approximately 370 homes in the Sagamore subdivision … have been lost. There’s a potential of 210 homes lost in Old Town Superior,” Pelle said at a news conference Thursday.
“Due to the magnitude and intensity of this fire, and its presence in such a heavily populated area, we would not be surprised if there are injuries or fatalities,” he continued.
Evacuation orders were first issued for all residents in the town of Superior, Colorado, with a population of about 13,000, and a short time later for the adjacent municipality of Louisville, home to more than 18,000 residents, the Boulder County emergency management office said on Twitter.
The swiftly spreading prairie grass fire was believed to have been ignited by sparks from power lines and transformers toppled by high winds on Colorado’s drought-parched Front Range, according to Boulder County Sheriff Joe Pelle.
Overnight, authorities lifted all evacuation orders and pre-evacuation warnings for residents outside of Boulder County, including residents in Broomfield and Westminster due to cooler temperatures and potential snow.
“It will be very chilly as we ring in the new year tonight. At midnight, temperatures will be in the teens to single digits while wind chills will be below zero in spots. Snow will be falling across the majority of the area at midnight,” the National Weather Service in Boulder said.
Polis declared a state of emergency allowing use of disaster funding to support emergency response efforts in Boulder County and to allow mobilization of the Colorado National Guard and other state resources as needed.
The fire on the outskirts of the Denver metropolitan area, left dry from drought gripping eastern Colorado, follows several days of heavy snow in the Rocky Mountains to the west. However, forecasts call for snow to hit Denver and eastern Colorado starting on Friday.
Reuters contributed to this report.