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The fire was “fueled by drought and hurricane-force winds.” It “jumped from one home to the next,” the local news later reported, and “moved in unpredictable and unprecedented ways.” Camera phone videos showed shaky scenes of last-minute evacuations — a “dizzyingly chaotic display of improvisation and panic.” The fire had apparently ignited in dry invasive grasses outside of town, perhaps due to a downed power line, before blowing into an unstoppable “urban firestorm.” Airborne embers destroyed hundreds of structures, leaving behind ashen ruins that survivors said looked like a war zone.
It was December 30, 2021. The Marshall fire would become the most destructive in Colorado’s history, ultimately killing two people, causing 35,000 to flee, and destroying more than 1,000 homes and businesses outside of Boulder. But to an untrained eye, the landscape hardly looked like a place where a wildfire could break out; after all, there was no forest. “It was 200 yards from a Costco — why would I have to worry about fire?” one survivor recounted to The Washington Post afterward. “It’s, like, suburbia, you know?”
But grass fires are a growing danger in the United States, even if they lack the iconic imagery of the forest fires that tend to dominate the news this time of year. The 2018 Martin fire in Nevada, the largest in the state’s history, burned 435,000 acres of invasive cheatgrass and at one point stretched 54 miles long. The 2006 East Amarillo Complex fire in Texas blackened almost a million acres. And the wildfires in Maui this month were the deadliest in modern U.S. history, in part because they ignited in highly flammable non-native grasses, which burn hot, fast, and unpredictably.
“They’re too intense for firefighters to get next to with either ‘dozers or engines,” Brad Smith, the Predictive Services department head at Texas A&M Forest Service, told me of the wind-driven grass fires he sees across Texas. “They also move too fast, so it’s dangerous to put people out in front of these fires. It’s often the case we have to wait either for the weather to change or for the fire to move into a more favorable fuel type,” such as plowed agricultural land, before first responders can get it under control.
I had reached out to Smith after seeing him dispense grassland firefighting advice in a 2011 educational video for firefighters titled, “Oh, It’s Just a Grass Fire.” Produced by the Wildland Fire Lessons Learned Center — a grimly named government agency that exists to “share lessons and knowledge within the entire wildland fire community” — the video was apparently intended to head off dismissals of what it calls a “potentially underestimated fuel type.”
Such an underestimation in the industry comes from the fact that grass fires can actually have “a few advantages” for wildland firefighters, as authors Justin Angle and Nick Mott write in their forthcoming guideThis Is Wildfire. “There are a lot of fire-fighting strategies that are just more feasible in a grassy landscape that’s more open and has more fuel breaks like roads and bodies of water,” the authors go on to explain. “In addition, the fuel type is more homogenous (and therefore predictable) compared with a mountain ecosystem.”
But throw in high winds, and all of a sudden grassland fires can become a completely different beast. “People think [wildfires] just move in one direction, but winds generally quarter,” Smith said. “So let’s say you have a north wind; you think, Well, [the fire] is going south. But if you get a 45-degree change in direction, that fire can move left or right for short periods of time very quickly. That can catch people by surprise.” In the instructional video, this point is made with the cautionary tale of Destry Horton, a father of two who was killed fighting a grass fire in Oklahoma in 2006.
But if even firefighters need the occasional somber refresher to take grass fires seriously, then many of the rest of us have likely barely registered them as a threat. “I think a lot of people look at a grass fire and feel like, ‘Well, I could just go stomp it out,’” Barb Satink Wolfson, the University of California’s Cooperative Extension fire advisor for Monterey, San Benito, Santa Clara, and Santa Cruz counties, told me.
Perhaps that’s partially because “forest fire” is often interchanged with “wildfire,” inadvertently evoking the conflagration out of Bambi: popping evergreen trees, flames reaching for the sky, adorable woodland animals running for cover. Reality looks a little different: Grassland pasture and range make up 60% of land use in the Mountain West and about 29% of land use in the Pacific Coast states, the most recent survey by the United States Department of Agriculture found (compared to 18% and 29% forest-use land, respectively).
Fire statistics seem to bear that out: In a study of burns in 11 western states between 1984 and 2020, only 35% were actually in forests, Denver’s 5280 magazine reports. In another cited study, local fire departments “responded to forest fires just 7% of the time, compared to 39% for grass fires.” Smith also told me that of the 30 largest fires in Texas since 2000, 28 had “occurred in our grass-dominant fuel-scape in West Texas.”
The tragic consequence of the public not taking grass fires seriously — or not knowing to take them seriously — is that many people who live in wildland-urban interface communities near or adjacent to natural, undeveloped lands might not have made the proper wildfire preparations or have an evacuation plan because the fire threat feels remote.
That can prove deadly. A quarter of Hawaii is covered in highly flammable non-native grasses and “virtually every community [in the state] is on a wildland-urban interface,” one fire manager recently told Wired. Yet the communities were unsuspecting and unprepared for the fire that swept through Lahaina and the surrounding landscape last week. Part of that is because fire is “not something that has been a part of ... society in Hawaii,” Satink Wolfson said, adding: “There isn’t a big history of people telling [residents]: ‘You need metal gutters, you need to make your home fire safe.’”
Though fire is not a historic part of the ecology of Hawaii, it is in North American grasslands, where Indigenous communities have practiced cultural burning for centuries upon centuries. But non-native grass species are likewise disrupting these natural cycles in the western United States, since invasive plants tend to grow thickly and contiguously, unlike native perennials that grow in more isolated clumps that help naturally break up fires. By one estimate, invasive grasses can more than triple a region’s susceptibility to wildfire.
Making matters worse, non-native grasses tend to quickly colonize and outcompete native plants after burns, in effect bridging fire further and further into landscapes where it doesn’t belong, such as deserts — or urban environments. “Those non-native herbaceous species are like the wick,” Max Moritz, a Cooperative Extension wildfire specialist and adjunct professor at U.C. Santa Barbara’s Bren School of Environmental Science & Management, told me. “They’re the place that fire can get a foothold on the landscape, even if the landscape wasn’t supposed to burn very often from a fire ecology perspective.”
Increasingly, attention in the West has focused on allowing “good fires” to run their course — grass fires included. “I would love to see CalFire use natural ignitions to reduce fire hazard and to improve ecosystem health,” Satink Wolfson said. “I’ve already seen so many fires put out this year that could have had a positive impact.” Moritz’s focus is on better land-use planning, including rehabilitating abandoned farmlands into working buffer zones. Both Satink Wolfson and Moritz floated strategic grazing as another possibility. But everyone agrees: Something needs to be done.
“Grasslands — there’s a lot of area there to manage if you are hoping to reduce the ignition potential,” Moritz said, then ominously warned: “It’s almost all ignitable.”
Read more about grass fires:
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Recovering from the Los Angeles wildfires will be expensive. Really expensive. Insurance analysts and banks have already produced a wide range of estimates of both what insurance companies will pay out and overall economic loss. AccuWeatherhas put out an eye-catching preliminary figure of $52 billion to $57 billion for economic losses, with the service’s chief meteorologist saying that the fires have the potential to “become the worst wildfire in modern California history based on the number of structures burned and economic loss.” On Thursday, J.P. Morgan doubled its previous estimate for insured losses to $20 billion, with an economic loss figure of $50 billion — about the gross domestic product of the country of Jordan.
The startlingly high loss figures from a fire that has only lasted a few days and is (relatively) limited in scope show just how distinctly devastating an urban fire can be. Enormous wildfires thatcover millions of acres like the 2023 Canadian wildfires can spew ash and particulate matter all over the globe and burn for months, darkening skies and clogging airways in other countries. And smaller — and far deadlier fires — than those still do not produce the same financial roll.
It’s in coastal Southern California where you find large population centers areas known by all to be at extreme risk of fire. And so a fire there can destroy a whole neighborhood in a few hours and put the state’s insurance system into jeopardy.
One reason why the projected economic impacts of the fires are so high is that the structures that have burned and the land those structures sit on are very valuable. Pacific Palisades, Malibu, and Santa Monica contain some of the most sought-after real estate on planet earth, with typical home prices over $2 million. Pacific Palisades itself has median home values of around $3 million, according to JPMorgan Chase.
The AccuWeather estimates put the economic damage for the Los Angeles fires at several times previous large, urban fires — the Maui wildfire in 2023 was estimated to cause around $14 billion of economic loss, for example — while the figure would be about a third or a quarter of a large hurricane, which tend to strike areas with millions of people in them across several states.
“The fires have not been contained thus far and continue to spread, implying that estimates of potential economic and insured losses are likely to increase,” the JPMorgan analysts wrote Thursday.
That level of losses would make the fires costlier in economic terms than the 2018 Butte County Camp Fire, whose insured losses of $10 billion made it California’s costliest at the time. That fire was far larger than the Los Angeles fires, spreading over 150,000 acres compared to just over 17,000 acres for the Palisades Fire and over 10,000 acres for the Eaton Fire. It also led to more than 80 deaths in the town of Paradise.
So far, around 2,000 homes have been destroyed,according to the Los Angeles Times,a fraction of the more than 19,000 structures affected by the Camp Fire. The difference in estimated losses comes from the fact that homes in Pacific Palisades weigh in at more than six times those in rural Butte, according to JPMorgan.
While insured losses get the lion’s share of attention when it comes to the cost impacts of a natural disaster, the potential damages go far beyond the balance sheet of insurers.
For one, it’s likely that many affected homeowners did not even carry insurance, either because their insurers failed to renew their existing policies or the homeowners simply chose to go without due to the high cost of what insurance they could find. “A larger than usual portion of the losses caused by the wildfires will be uninsured,” according to Morningstar DBRS, which estimated total insured losses at more than $8 billion. Many homeowners carry insurance from California’s backup FAIR Plan, which may itself come under financial pressure, potentially leading to assessments from the state’s policyholders to bolster its ability to pay claims.
AccuWeather arrived at its economic impact figure by looking not just at losses from property damage but also wages that go unearned due to economic activity slowing down or halting in affected areas, infrastructure that needs to be repaired, supply chain issues, and transportation snarls. Even when homes and businesses aren’t destroyed, people may be unable to work due to evacuations; businesses may close due to the dispersal of their customers or inability of their suppliers to make deliveries. Smoke inhalation can lead to short-, medium-, and long-term health impacts that take a dent out of overall economic activity.
The high level of insured losses, meanwhile, could mean that insurers’ will see less surplus and could have to pay more for reinsurance, Nancy Watkins, an actuary and wildfire expert at Milliman, told me in an email. This may mean that they would have to shed yet more policies “in order to avoid deterioration in their financial strength ratings,” just as California has been trying to lure insurers back with reforms to its dysfunctional insurance market.
The economic costs of the fire will likely be felt for years if not decades. While it would take an act of God far stronger than a fire to keep people from building homes on the slopes of the Santa Monica Mountains or off the Pacific Coast, the city that rebuilds may be smaller, more heavily fortified, and more expensive than the one that existed at the end of last year. And that’s just before the next big fire.
Suburban streets, exploding pipes, and those Santa Ana winds, for starters.
A fire needs three things to burn: heat, fuel, and oxygen. The first is important: At some point this week, for a reason we have yet to discover and may never will, a piece of flammable material in Los Angeles County got hot enough to ignite. The last is essential: The resulting fires, which have now burned nearly 29,000 acres, are fanned by exceptionally powerful and dry Santa Ana winds.
But in the critical days ahead, it is that central ingredient that will preoccupy fire managers, emergency responders, and the public, who are watching their homes — wood-framed containers full of memories, primary documents, material wealth, sentimental heirlooms — transformed into raw fuel. “Grass is one fuel model; timber is another fuel model; brushes are another — there are dozens of fuel models,” Bobbie Scopa, a veteran firefighter and author of the memoir Both Sides of the Fire Line, told me. “But when a fire goes from the wildland into the urban interface, you’re now burning houses.”
This jump from chaparral shrubland into neighborhoods has frustrated firefighters’ efforts to gain an upper hand over the L.A. County fires. In the remote wilderness, firefighters can cut fire lines with axes, pulaskis, and shovels to contain the blaze. (A fire’s “containment” describes how much firefighters have encircled; 25% containment means a quarter of the fire perimeter is prevented from moving forward by manmade or natural fire breaks.)
Once a fire moves into an urban community and starts spreading house to house, however, as has already happened in Santa Monica, Pasadena, and other suburbs of Los Angeles, those strategies go out the window. A fire break starves a fire by introducing a gap in its fuel; it can be a cleared strip of vegetation, a river, or even a freeway. But you can’t just hack a fire break through a neighborhood. “Now you’re having to use big fire engines and spray lots of water,” Scopa said, compared to the wildlands where “we do a lot of firefighting without water.”
Water has already proven to be a significant issue in Los Angeles, where many hydrants near Palisades, the biggest of the five fires, had already gone dry by 3:00 a.m. Wednesday. “We’re fighting a wildfire with urban water systems, and that is really challenging,” Los Angeles Department of Water and Power CEO Janisse Quiñones explained in a news conference later that same day.
LADWP said it had filled its 114 water storage tanks before the fires started, but the city’s water supply was never intended to stop a 17,000-acre fire. The hydrants are “meant to put out a two-house fire, a one-house fire, or something like that,” Faith Kearns, a water and wildfire researcher at Arizona State University, told me. Additionally, homeowners sometimes leave their sprinklers on in the hopes that it will help protect their house, or try to fight fires with their own hoses. At a certain point, the system — just like the city personnel — becomes overwhelmed by the sheer magnitude of the unfolding disaster.
Making matters worse is the wind, which restricted some of the aerial support firefighters typically employ. As gusts slowed on Thursday, retardant and water drops were able to resume, helping firefighters in their efforts. (The Eaton Fire, while still technically 0% contained because there are no established fire lines, has “significantly stopped” growing, The New York Times reports). Still, firefighters don’t typically “paint” neighborhoods; the drops, which don’t put out fires entirely so much as suppress them enough that firefighters can fight them at close range, are a liability. Kearns, however, told me that “the winds were so high, they weren’t able to do the water drops that they normally do and that are an enormous part of all fire operations,” and that “certainly compounded the problems of the fire hydrants running dry.”
Firefighters’ priority isn’t saving structures, though. “Firefighters save lives first before they have to deal with fire,” Alexander Maranghides, a fire protection engineer at the National Institute of Standards and Technology and the author of an ongoing case study of the 2018 Camp fire in Paradise, California, told me. That can be an enormous and time-consuming task in a dense area like suburban Los Angeles, and counterintuitively lead to more areas burning down. Speaking specifically from his conclusions about the Camp fire, which was similarly a wildland-urban interface, or WUI fire, Maranghides added, “It is very, very challenging because as things deteriorate — you’re talking about downed power lines, smoke obstructing visibility, and you end up with burn-overs,” when a fire moves so quickly that it overtakes people or fire crews. “And now you have to go and rescue those civilians who are caught in those burn-overs.” Sometimes, that requires firefighters to do triage — and let blocks burn to save lives.
Perhaps most ominously, the problems don’t end once the fire is out. When a house burns down, it is often the case that its water pipes burst. (This also adds to the water shortage woes during the event.) But when firefighters are simultaneously pumping water out of other parts of the system, air can be sucked down into those open water pipes. And not just any air. “We’re not talking about forest smoke, which is bad; we’re talking about WUI smoke, which is bad plus,” Maranghides said, again referring to his research in Paradise. “It’s not just wood burning; it’s wood, plastics, heavy metals, computers, cars, batteries, everything. You don’t want to be breathing it, and you don’t want it going into your water system.”
Water infrastructure can be damaged in other ways, as well. Because fires are burning “so much hotter now,” Kearns told me, contamination can occur due to melting PVC piping, which releases benzene, a carcinogen. Watersheds and reservoirs are also in danger of extended contamination, particularly once rains finally do come and wash soot, silt, debris, and potentially toxic flame retardant into nearby streams.
But that’s a problem for the future. In the meantime, Los Angeles — and lots of it — continues to burn.
“I don’t care how many resources you have; when the fires are burning like they do when we have Santa Anas, there’s so little you can do,” Scopa said. “All you can do is try to protect the people and get the people out, and try to keep your firefighters safe.”
Plus 3 more outstanding questions about this ongoing emergency.
As Los Angeles continued to battle multiple big blazes ripping through some of the most beloved (and expensive) areas of the city on Thursday, a question lingered in the background: What caused the fires in the first place?
Though fires are less common in California during this time of the year, they aren’t unheard of. In early December 2017, power lines sparked the Thomas Fire near Ventura, California, which burned through to mid-January. At the time it was the largest fire in the state since at least the 1930s. Now it’s the ninth-largest. Although that fire was in a more rural area, it ignited for some of the same reasons we’re seeing fires this week.
Read on for everything we know so far about how the fires started.
Five major fires started during the Santa Ana wind event this week:
Officials have not made any statements about the cause of any of the fires yet.
On Thursday morning, Edward Nordskog, a retired fire investigator from the Los Angeles Sheriff’s Department, told me it was unlikely they had even begun looking into the root of the biggest and most destructive of the fires in the Pacific Palisades. “They don't start an investigation until it's safe to go into the area where the fire started, and it just hasn't been safe until probably today,” he said.
It can take years to determine the cause of a fire. Investigators did not pinpoint the cause of the Thomas Fire until March 2019, more than two years after it started.
But Nordskog doesn’t think it will take very long this time. It’s easier to narrow down the possibilities for an urban fire because there are typically both witnesses and surveillance footage, he told me. He said the most common causes of wildfires in Los Angeles are power lines and those started by unhoused people. They can also be caused by sparks from vehicles or equipment.
At about 27,000 acres burned, these fires are unlikely to make the charts for the largest in California history. But because they are burning in urban, densely populated, and expensive areas, they could be some of the most devastating. With an estimated 2,000 structures damaged so far, the Eaton and Palisades fires are likely to make the list for most destructive wildfire events in the state.
And they will certainly be at the top for costliest. The Palisades Fire has already been declared a likely contender for the most expensive wildfire in U.S. history. It has destroyed more than 1,000 structures in some of the most expensive zip codes in the country. Between that and the Eaton Fire, Accuweather estimates the damages could reach $57 billion.
While we don’t know the root causes of the ignitions, several factors came together to create perfect fire conditions in Southern California this week.
First, there’s the Santa Ana winds, an annual phenomenon in Southern California, when very dry, high-pressure air gets trapped in the Great Basin and begins escaping westward through mountain passes to lower-pressure areas along the coast. Most of the time, the wind in Los Angeles blows eastward from the ocean, but during a Santa Ana event, it changes direction, picking up speed as it rushes toward the sea.
Jon Keeley, a research scientist with the US Geological Survey and an adjunct professor at the University of California, Los Angeles told me that Santa Ana winds typically blow at maybe 30 to 40 miles per hour, while the winds this week hit upwards of 60 to 70 miles per hour. “More severe than is normal, but not unique,” he said. “We had similar severe winds in 2017 with the Thomas Fire.”
Second, Southern California is currently in the midst of extreme drought. Winter is typically a rainier season, but Los Angeles has seen less than half an inch of rain since July. That means that all the shrubland vegetation in the area is bone-dry. Again, Keeley said, this was not usual, but not unique. Some years are drier than others.
These fires were also not a question of fuel management, Keeley told me. “The fuels are not really the issue in these big fires. It's the extreme winds,” he said. “You can do prescription burning in chaparral and have essentially no impact on Santa Ana wind-driven fires.” As far as he can tell, based on information from CalFire, the Eaton Fire started on an urban street.
While it’s likely that climate change played a role in amplifying the drought, it’s hard to say how big a factor it was. Patrick Brown, a climate scientist at the Breakthrough Institute and adjunct professor at Johns Hopkins University, published a long post on X outlining the factors contributing to the fires, including a chart of historic rainfall during the winter in Los Angeles that shows oscillations between very wet and very dry years over the past eight decades. But climate change is expected to make dry years drier in Los Angeles. “The LA area is about 3°C warmer than it would be in preindustrial conditions, which (all else being equal) works to dry fuels and makes fires more intense,” Brown wrote.