Author(s): Angelo Verzoni. Published on May 1, 2017.

Structure Survival

Heavy losses in recent wildfires in California and Canada raise a central question: How can we better protect homes and other structures against wildfire?


In 2015, California experienced a spate of devastating wildfires, including one that destroyed nearly 2,000 structures—the most of any wildfire in the state since 2003. That fire and another, which destroyed over 800 structures, accounted for almost $2 billion in property damage.

The destruction came amid aggressive and controversial efforts by the California Department of Forestry and Fire Protection, or CAL FIRE, to prevent wildfires. Today, CAL FIRE says those efforts are starting to pay off, but it has also identified areas for improvement, namely in preventing structure loss in wildfire events. A pair of education sessions at the NFPA Conference & Expo will explore the issue of structure loss in the wildland/urban interface, or WUI, and the challenges faced by firefighters, public educators, homeowners, and others.

In 2011, a California assemblyman proposed a first-of-its-kind bill that imposed a $150 annual fee for roughly 800,000 people who own homes in the state’s 31 million acres of unincorporated land known as the “state responsibility area,” where CAL FIRE is responsible for fighting fires—many of them wildfires. The bill was met with backlash from some who argued it was an unfair tax, but the measure was signed into law nonetheless.

Six years into the law, the state is seeing specific cases in which wildfires have been stopped because of prevention efforts that were made possible by the money collected from the fees, according to David Shew, staff chief of planning and risk analysis at CAL FIRE. “We’re far enough into the law that we’re beginning to see examples of where prevention work that was funded by the fee reduced the impact of certain wildfires, preventing them from becoming bigger and more destructive,” Shew told NFPA Journal. “The fee is leading to fewer wildfires.”

Specifically, the money has allowed CAL FIRE to increase public education about wildfire and wildfire prevention and create more defensible spaces, or areas where vegetation and other wildfire fuel is reduced to slow the spread of wildfire, Shew said. There has also been a rise in the number of Firewise communities in California since the law was passed, he said, which could be attributed to the increase in education.

A 2016 wildfire menaces property in California.

Ready or Not A 2016 wildfire menaces property in California. The state says it is seeing progress in home-ignition prevention as a result of a program that imposes an annual fee on residents in certain fire-prone areas. The money is used for an array of mitigation and prevention efforts. Photograph: Getty Images

One area Shew said is lacking, however, is teaching residents the notion of “solidifying” or “hardening” homes and other structures—sealing cracks, crevices, and other areas where wind-blown embers from a wildfire can become trapped and ignite a fire. The absence of hardened homes can lead to structures being destroyed by the thousands during wildfires, he said. Shew will lead an education session at the Conference & Expo that will address structure hardening and other efforts by CAL FIRE to prevent structure loss in the WUI.

“The Beast”

Complementing Shew’s talk is another education session that will look at the structure-protection lessons learned from a massive wildfire that tore through Western Canada last year, which reinforce much of what CAL FIRE is trying to teach residents in California.

A wildfire started on Sunday, May 1, 2016, in a bog near Fort McMurray, a major hub of oil production in Alberta. Written off at first as merely another wildfire in an area that’s used to them, it took just a few hours for fire officials to realize that the blaze was not an ordinary fire event; conditions meant the fire was growing fast and roaring toward the city of roughly 60,000 residents. That night a state of emergency was declared in Fort McMurray.

The following days proved stressful and sleepless for fire officials, who were tasked with coordinating the evacuation of over 90,000 people along just one major highway. “I really believed at the end of Tuesday, if we wake up at first light and we’ve got 50 percent of our homes left and we’ve only killed a few thousand people, we’d have done well. That’s how bad I felt,” Darby Allen, fire chief of Wood Buffalo, a municipality that includes Fort McMurray, told the Canadian Broadcasting Corporation.

In the end, the human cost wasn’t as bad as Allen feared; nobody died in the fire. But approximately 1.5 million acres were burned before the fire, nicknamed “The Beast,” was mostly contained two months later. The fire left vast swaths of Fort McMurray looking like a warzone, with cars reduced to paint-stripped bodies, homes to concrete foundations, and trees to blackened trunks. About 15 percent of the city was destroyed, including an estimated 2,400 structures. Loss estimates for the fire approached $10 billion—including direct losses like property damage as well as indirect losses like lost wages and reduced oil production—making it the costliest disaster in Canadian history.

A few months after the fire, Alan Westhaver, a wildfire behavior analyst, published a report for the Toronto-based Institute for Catastrophic Loss Reduction that reinforced the importance of wildfire prevention and preparedness efforts. Westhaver will lead an education session on the report and the lessons learned from the Fort McMurray wildfire at the Conference & Expo.

Westhaver’s report, “Why Some Homes Survived: Learning from the Fort McMurray Wildfire Disaster,” concluded that structure loss in the fire was not random, but instead dependent on homes’ wildfire preparedness as established by guidelines put forth by FireSmart, a Canadian wildfire preparedness program similar to NFPA’s Firewise. According to the report, 81 percent of homes that survived the fire had a FireSmart hazard rating of low to moderate, meaning they were well-prepared for a wildfire, and all of the homes that survived despite extreme exposure to the fire had a low hazard rating. Conversely, most of the homes that were destroyed in the fire had high to extreme FireSmart hazard ratings.

While there is no “silver bullet,” or one measure to ensure a home’s survival in a wildfire, Westhaver’s report concludes, there can be an “Achilles’ heel,” or one weakness, even when all other FireSmart guidelines are followed, that can lead to a home’s ignition and destruction.

Shew, the CAL FIRE official, agrees. “Preventing structure loss during wildland fires is a combination of things,” he said. “It’s not just one thing. You could have all the defensible space you want, but if your home hasn’t been solidified to resist the intrusion of embers blowing during a wildfire, you will have a very, very high risk of having your home destroyed.”


It’s likely that had more homes been solidified, or hardened, in Fort McMurray, the fire would have caused less structure loss. “The investigator discounted direct contact from flames or radiant heat of the fire as being significant sources of ignition,” Westhaver’s report says. “Instead, it was concluded that wind-driven embers were the most probable cause for the majority of early home ignitions in the zone where the fire made its transition from forest into urban neighborhoods.”

Michele Steinberg, who heads NFPA’s Wildfire Division, said all wildfire prevention research backs up the notion that saving structures in wildfires doesn’t come down to any one measure. “It’s a package deal,” she said. “It’s the home itself and everything around it that’s going to drive the potential for ignition. If you’ve got a well-prepared lawn with a lot of defensible space that’s been cleared of vegetation, but you have some junk vehicles next to your house or an aging wood roof or spaces where embers can get trapped, it is definitely a problem.”

Not just a Western problem

With the Conference & Expo in Boston this year, Shew and Westhaver will try to appeal to a crowd that includes fire service members from the East Coast, where wildfire has not traditionally been seen as a major threat. But Shew and Steinberg were quick to point out that misconception, and that wildfire should be on the radar of everyone in the fire service.

“Just look at what happened in Gatlinburg,” Steinberg said, referring to the November wildfire that tore through Eastern Tennessee, killing 14 people and destroying or damaging over 2,400 structures. “Wildfire is present in pretty much every state in the country.”

Likewise, Shew pointed to wildfires in states like Florida, New Jersey, and Maine. In fact, he said, the most devastating wildfire in American history occurred in 1871 in Wisconsin. The Peshtigo Fire killed over 1,000 people and scorched more than a million acres of land as it roared through Northeast Wisconsin. It just so happened that the blaze occurred on the same day as the Great Chicago Fire and was overshadowed by it.

“There are so many examples of significant, catastrophic wildfires that have occurred outside of the West Coast,” Shew said.

ANGELO VERZONI is staff writer for NFPA Journal. Top Photograph: Getty Images