BOULDER COUNTY, Colorado (KDVR) — High winds Thursday wreaked havoc throughout Colorado’s Boulder County, overturning big rigs, causing power outages, destroying structures and helping spark what has already become the most destructive wildfire in the state’s history.

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Friday’s sunrise will bring the first glimpse at the devastation wrought by the Marshall Fire, which had consumed nearly 600 homes by sundown Thursday and continued its tear through Boulder County overnight.

Injuries, fatalities uncertain

Boulder County Sheriff Joe Pelle called it “a harrowing day in Boulder County.”

With gusts reaching at least 105 mph, the winds — paired with extremely dry conditions — sparked two significant fires in the county. The Middle Fork Fire was reported just before 10:30 a.m. near North Foothills Highway and Middle Fork Road, but it was attacked quickly and under monitoring by late afternoon with no structures were reported lost, Pelle said.

The Marshall Fire was reported just after 11 a.m. at South Foothills Highway and Marshall Road. It grew and spread quickly throughout the day, reaching around 1,600 acres by 5 p.m. Mandatory evacuations were issued in Louisville, Superior and unincorporated Boulder County.

“This was a horrific event,” Pelle said. He said the fire was consuming football-field lengths in seconds, with some responders saying they had never seen anything like it.

Gov. Jared Polis soon declared a state of emergency, and the Federal Emergency Management Agency approved funding to help with the efforts.

Avista Adventist Hospital in Louisville, with flames within a block or two of the facility, was evacuated, along with other care centers that were suffering from smoke exposure. Louisville Police Chief Dave Hayes said his department’s building was evacuated because of fires burning nearby.

Parts of Broomfield and Westminster were also under evacuation orders, with parts of Arvada under pre-evacuation warning, but all were lifted before midnight.

A police officer reported an eye injury when wind-blown debris flew into it, and another six people impacted by the fire were being treated at an area hospital.

No one had been reported missing as of Thursday evening. Pelle said because of “the intensity of the fire and its presence in such a heavily populated area, we would not be surprised if there are injuries or fatalities.”

The fast-moving fire made it difficult for firefighters to reach impacted areas, often forcing them into retreat. Wind conditions grounded aircraft that could be used at night to help map the fire.

At a 5 p.m. news conference, Pelle said an estimated 370 homes in the Sagamore subdivision, just west of Superior, were lost, along with another 210 homes in Old Town Superior. Between Superior and Marshall, near Eldorado Springs, “a number of homes and small subdivisions” were also lost.

The Target shopping complex in Superior was on fire, and the Element hotel there was fully engulfed. Pelle later said businesses and strip malls near US 36 and McCaslin Boulevard were also impacted.

‘There were people who would not evacuate’

The calculated losses are expected to balloon on Friday when crews are able to make their first assessments under daylight. Officials will hold a media briefing at 10 a.m. Friday.

Polis, who lives in Boulder County, pointed out that while Colorado saw its three largest wildfires in the history of the state in 2020, with each one reaching more than 200,000 acres, the burned lands were largely unpopulated wilderness. The area impacted by the fast-moving Marshall Fire was largely around suburban developments and commercial properties.

“It’s like the neighborhood that you live in,” Polis said. “It’s like the neighborhood that any of us live in. So 1,600 acres near a population center can be, and is, in this case, absolutely devastating.”

Officials spent Thursday “rushing ahead of those flames trying to get people out of harm’s way,” Pelle said. Responders often had to turn away as they approached neighborhoods because of the extreme heat. Some front-line responders live in the areas under evacuation and fought the fires without knowing how their own homes had fared.

Pelle said Friday will bring the first opportunity for officials to truly understand the fire’s destruction and whether it caused any casualties.

“There were people who would not evacuate,” Pelle said. “We have a number of reports of deputies who actually contacted people who refused to evacuate, and we know those homes are gone. So we are praying that they got out in time.”

95% of Boulder County under severe or extreme drought

The National Weather Service in Boulder pointed to the recent record dryness in the area as “one of the many factors” that led to the fire. Denver has been the driest on record since July, and snowfall is at record lows.

Nearly 95% of Boulder County is under severe or extreme drought.

“With any snow on the ground, this absolutely would not have happened in the way that it did,” snow hydrologist Keith Musselman told the Associated Press on Thursday.

Musselman was at home when Thursday’s fires broke out not far away. He said this severe fire risk is expected in September and October following a dry summer, but the lack of any precipitation this late in the season is highly unusual.

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

Officials believe downed power lines caused the fire, although the information is still preliminary.

The Associated Press contributed to this report.