Colorado Wildfire Destruction Was Caused by Embers Flung for Miles
Communities far from flammable forests are increasingly at risk, as drought causes embers to burn hotter and travel farther
By Dan Frosch and Jim Carlton | Photographs by Rachel Woolf for The Wall Street Journal
A view Wednesday of the remains of Shelagh Turner's house, which was destroyed in the Marshall Fire, in Louisville, Colo. She had lived in the home for 27 years.
The Colorado suburbs of Louisville and Superior at the base of the Rocky Mountains were always thought to be safely removed from the wildfires that often burned in the foothills above.

But last week, a grasslands fire destroyed more than 1,000 homes in and around the two communities near Boulder, as powerful winds rained down embers on subdivisions that fires had never before touched.

The ember-fueled Marshall Fire, which scorched 6,067 acres on Dec. 30, is the latest example of a growing threat to similar cities in the West that aren’t directly adjacent to historically fire-prone areas blanketed with forest and brush. The region’s historic drought is creating conditions in which embers burn hotter, travel farther and more easily spark parched land. The drought is caused in part by climate change, according to scientists at Colorado State University’s Colorado Climate Center.

Boulder County, located less than 30 miles northwest of Denver, already has some of Colorado’s most robust fire-protection plans for its foothills and mountain towns. But officials acknowledge they never considered that a wildfire could spread to suburban communities along the plains below.

“This fire is certainly a game changer for us,” said Seth McKinney, fire-management officer for the Boulder County Sheriff’s Office.

“It redefines what we think of as the wildland-urban interface,” he added, referring to areas where development meets nature and which fire researchers have long believed face the highest risk of wildfire danger.

Boulder County Sheriff Joe Pelle said this week that authorities are still investigating the cause of the Marshall Fire, which forced tens of thousands to evacuate and has left two people missing.
Shelagh Turner, right, with her daughter after finding an item from the debris of the family’s home, destroyed by the Marshall fire.
A close-up of family-heirloom china that was found.
Researchers and local officials say the area’s drought undoubtedly played a role. Denver posted its driest and warmest period between June 1 and Dec. 29—the day before the fire—since 1933, according to the Colorado Climate Center at Colorado State University. Those conditions followed an unusually wet spring that spawned a bumper crop of tall prairie grasses, which provided fuel for the fire.

Embers were flung for miles by winds that topped 100 mph, said Dan Dallas, a U.S. Forest Service supervisor and an incident commander on the fire.

Some landed in subdivisions in Louisville and Superior, a suburban city and town of 21,000 and 13,000, respectively, where homes got caught in an inferno that spread to other residences. 

Even local officials long familiar with the region’s wildfire danger were caught off guard.

Boulder County Commissioner Matt Jones was driving back from photographing the fire after it first started burning on grasslands 6 miles from his home when his wife called to tell him they were being evacuated.

“This can’t be happening,” Mr. Jones, who spent years doing wildland firefighting work, recalled thinking. “Wildland fires don’t hit Louisville, Colo.”

A similar ember storm sparked by the 2017 Tubbs Fire wiped out much of the community of Coffey Park in Santa Rosa, Calif., after jumping lanes of a freeway. In 2011, embers from a large wildfire in Bastrop County, Texas, helped propel flames for miles, destroying more than 1,600 homes.
Heavy snowfall has hampered search-and-recovery efforts in Colorado, with two people still missing from the Marshall Fire that burned about 1,000 homes and other structures. Many residents were overwhelmed as they trudged through snow to dig for belongings in hot debris. Photo: Michael Ciaglo/Getty Images
The growing risk caused by embers poses a particular threat to areas once considered safely removed from designated fire-risk zones, officials say. In addition to igniting dry land more easily, embers are getting bigger and hotter. Huge wildfires, which are more common, also create smoke columns that carry embers farther than they typically traveled in the past.

“No place is fire-safe, particularly in the West where you combine grasslands and chaparral with enduring drought,” said Char Miller, professor of environmental analysis at Pomona College in Claremont, Calif.

In Boulder County, fire officials spent years on mitigation strategies, including requiring new developments in fire-prone areas to create their own wildfire-protection plans.
Boulder County Commissioner Matt Jones near a fence in Louisville burned by the Marshall Fire last month.
But the efforts focused primarily on mountain towns and the foothills.

The county last year released fire-hazard maps that showed the risk to local homes from wildland blazes falling off significantly once fire reaches the plains around Louisville and Superior, said Mr. McKinney, the fire-management officer.

Fire researchers say communities such as those burned by the Marshall Fire will have to take many of the same precautions as their mountain counterparts, such as installing ember guards on rooftops and clearing flammable materials away from homes.

“What this event does is double down for us the need to be addressing how we build for wildfires the same way we do for hurricanes,” said Roy Wright, chief executive officer of the Insurance Institute for Business and Home Safety, an industry research group. “We assume for hurricanes those high winds will extend inland, so we need to presume for wildfires once you have ignition, those forces can extend miles into communities.”

Until last week, many residents in neighborhoods decimated by the Marshall Fire never worried much about the wildfires’ reaching their front doors. Last Thursday morning, Shelagh Turner, a 64-year-old retired teacher, had returned from running errands when a neighbor frantically told her she had 15 minutes to get out. Ms. Turner, who has lived in the same two-story, wood-frame home in Louisville for 27 years, was stunned.

Never having evacuated before, she called her daughters and asked them to Google what she should take. She grabbed her important documents and some clothes and, in a moment of confusion, loaded her skis into her Subaru. The 25-minute drive to one daughter’s house took three hours on roads choked with fleeing cars, she said.

When Ms. Turner later returned to her neighborhood, she found a blackened heap of rubble where her house once stood. Among the few items that survived: her mailbox and a plant pot she’d had for 20 years in which she put flowers every spring.

“Never in a million years did I think it would be anything like this,” Ms. Turner said. “I always thought I’d be safe.”
A plant pot near where Shelagh Turner sat Wednesday was one of the few items that survived the fire that destroyed her home.
Santa Clara County FireSafe Council
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