The wildland urban interface: why wildfire fatalities seem so prevalent in the U.S.

Aug. 24, 2023, Washington – The oceanfront home on Maui’s western shore sits unscathed, family car in the driveway, its pristine red roof and well-tended yard an oasis of hope on a bleak landscape of ash and destruction.

The most enduring image of Hawaii’s wildfire tragedy is, in some ways, symbolic of the modern-day challenge of climate change: ensuring humanity can still thrive in an indiscriminate and unpredictable natural world.

In other ways, however, it is simply not good enough, argued Erica Fischer, a civil engineering professor at Oregon State University and an expert on the intersection between wildland fires and the urban environment.

“From a civil engineering perspective, we can say no, that is not resilience,” Fischer said of the famous Lahaina house.

“Resilience is when your neighbours’ homes are also standing and your whole community is still there, because the human part of it needs to be retained.”

The challenge is especially acute in the U.S., a nation of 332 million people where wildfires are becoming mass-casualty events, unlike in Canada, where an encroaching fire is still largely a matter of mass evacuations and narrow escapes.

What makes a wildfire deadly is typically a confluence of multiple factors, experts say – population size, the volatility of the fire itself and the ability and willingness of residents to evacuate quickly, among others.

The traditional approach has been to use wildfire mitigation practices such as debris management, controlled burns and public awareness to reduce the risk in the first place, but that’s no longer sufficient, Fischer said in an interview.

“I think what we’re seeing, and you’re seeing in Canada, is that that can not be our only prong, our only line of defence,” she said.

“We need to start simultaneously hardening our infrastructure and our communities, especially for these fires that are wind-driven, that are coming in quick, and where people need to evacuate.”

There is no comprehensive source of data in the U.S. on civilian wildfire casualties, partly because such incidents typically involve multiple agencies and jurisdictions.

Verisk, an international risk assessment and data analytics firm, estimates there are roughly 4.5 million homes in the U.S. – nearly half of those in California alone – that face a high or extreme risk from wildfires.

Compare that with the company’s Canadian data, which estimates the number of homes in B.C. in that same category at 259,100, and fewer than 31,000 in Alberta.

The 2021 fire in Lytton, B.C., claimed just two lives when it consumed a village that was home to about 250 people. And there were no fatalities in Fort McMurray in 2016 despite a monstrous blaze that destroyed some 2,400 homes, the single most costly wildfire catastrophe in Canadian history.

This year, despite what by all accounts has been the worst wildfire season ever in North America in terms of area burned, there have been only six fatalities in Canada, four of them firefighters.

The two civilian deaths were only tangentially related to the fires: a nine-year-old boy in B.C. who died following a smoke-induced asthma attack, and a hospital patient in Yellowknife who was in the process of being evacuated.

But regardless of fatality rates, neither country is confronting the threat properly, said Chris Dunn, an OSU forestry professor who specializes in wildfire management and how to manage the risk.

“We’re still sort of stuck in this mentality in the United States that it’s a forest problem – that the fires are out there in the forest,” Dunn said.

“They have moved into our communities, and we’re still even as a society not accepting that fact and therefore not responding accordingly … we’re not bridging that gap well yet.”

Engineers like Fischer point to a need for “home hardening” – retrofitting vulnerable homes with fire-resistant roofs and other materials, building new communities with more space between structures and changing the approach to urban landscaping to better ensure wildfire fuel like wood and brush is kept well away from structures.

That was the case of the solitary home in Lahaina, a 100-year-old building that was renovated in 2021 with a steel roof, fire-resistant wood and siding and stone materials around the structure to keep vegetation at bay.

Ironically, part of the reason wildfires are becoming more of a problem in populous countries is a shortage of wildfire, said Dave Calkin, a research forester with the U.S. Forest Service’s Rocky Mountain Research Station in Missoula, Mont.

“Fire is the answer to fire in a lot of places,” Calkin said.

“One of the biggest reasons we’re in the problem we are in the western U.S. is that we’ve done our best to remove fire from the landscape. In that attempt to remove fire, we’re essentially adding fuel to the fires of the future.”

Wildfire fatalities typically occur in the first 12 hours after ignition, said Calkin, who is quick to note he’s not an expert on Canada’s wildfire landscape. But a lack of fatalities there could be a function of lower population density and fires that are slow to reach the speed and scale necessary to threaten human life.

“I believe many of the largest and most damaging Canadian wildfires take longer to establish the potential for explosive growth and therefore there is more time to evacuate or prepare,” he said.

“When the very large wildfires take time to establish themselves in the U.S. … fatality rates are typically zero to very low.”

In Hawaii, efforts to quantify the loss of life are still ongoing. The death toll has reached 115 people, but more than 1,000 are still unaccounted for.

Outside of Maui, three of the five largest wildfires in U.S. history occurred in California in just the last five years, according to the Western Fire Chiefs Association.

One of them, the August Complex in 2020, was part of the state’s worst fire season on record, a year that produced 10,000 separate blazes, consumed nearly 17,500 square kilometres and claimed 133 lives.

The biggest? That one happened to start in Canada: the infamous 1825 Miramichi fire in New Brunswick, where a brutal heat wave and hurricane-force winds fuelled a fearsome and deadly blaze that reached as far south as Maine. At least 160 people were killed.

In 2022, the U.S. Forest Service launched a 10-year strategy aimed at helping to ease both the effect and mounting severity of wildfires across the country.

President Joe Biden’s administration is also spending $7 billion to build up the ranks of wildland firefighters, lower the amount of combustible fuel on forest floors and develop high-tech fire detection and location systems.

But the biggest challenge in the U.S. continues to be convincing homeowners in vulnerable areas of the steps, and expense, necessary to lower their risk – a challenge in a nation famous for fiercely guarding its independence.

Dunn and Fischer were recently helping Oregon develop an “exposure map” to better show residents and public officials in Oregon the areas with the greatest need for tighter regulations to better reduce the risk.

“The public backlash was so intense they had to pull the map,” Dunn said.

“People got really, really upset about it. And so that tells me, no, they’re not ready to accept that personal responsibility yet.”