Il cielo stava diventando arancione e le braci volavano dal fuoco quando Oney e Donna Carrell e il padre di Donna scapparono dalla loro casa in paradiso.

"Ho pensato, 'Oh, bene, la casa è fatta, '", ha detto Oney Carrell.

Alcuni giorni dopo, hanno imparato diversamente. La casa dei Carrell è sopravvissuta all'incendio più letale e distruttivo della storia della California con un paio di infissi deformati, un beccuccio parzialmente carbonizzato e un odore di fumo ostinato all'interno.

La maggior parte del loro quartiere è stata distrutta. Una guest house nel loro cortile, dove viveva il padre di Donna, fu ridotto in cenere, insieme a un paio di capannoni. Eppure la loro Studebaker del 1940 splendidamente restaurata è rimasta intatta nel garage.

L'arco di distruzione che il fuoco di campo ha scolpito nel paradiso è stato apparentemente casuale:perché alcune case sono state salvate e altre incenerite? Mentre milioni di californiani si preparano per un'altra stagione di incendi, un'analisi McClatchy dei registri degli incendi e delle proprietà mostra che la risposta potrebbe essere trovata in qualcosa di semplice come i tetti sopra le loro teste e l'anno in cui la loro casa è stata costruita.

Un codice edilizio di riferimento del 2008 progettato per le regioni a rischio di incendio della California, che richiedono tetti resistenti al fuoco, raccordo e altre misure di sicurezza—sembra aver protetto la casa dei Carrell e dozzine di altre simili dal fuoco di campo. Quell'anno segna un momento cruciale nella storia mortale e costosa dello stato di disastri naturali distruttivi.

Tutto detto, circa il 51 per cento delle 350 case unifamiliari costruite dopo il 2008 lungo il percorso del fuoco da campo non sono state danneggiate, secondo l'analisi di McClatchy dei dati di Cal Fire e dei registri delle proprietà della contea di Butte. Al contrario, solo il 18 per cento dei 12, 100 case costruite prima del 2008 sono sfuggite ai danni. Queste cifre non includono le case mobili, che bruciava quasi in egual misura indipendentemente dall'età.

"Questi sono ottimi standard; funzionano, " ha affermato l'ingegnere senior Robert Raymer della California Building Industry Association, che si è consultato con i funzionari statali sul regolamento edilizio.

Eppure, nonostante questa lezione, La California potrebbe finire per non essere all'altezza dei suoi sforzi per proteggere le case dal prossimo incendio.

Città di funghi come Folsom, dove un 11, lo sviluppo di 000 case sta sorgendo, hanno la capacità di aggirare gli standard di sicurezza statali nonostante i considerevoli rischi di incendio. Lo stato, che offre incentivi in ​​denaro per sostenere le vecchie case contro i terremoti, finora non ha fatto nulla per convincere i californiani a ristrutturare le case costruite prima del 2008 per la sicurezza antincendio.

Non ha aiutato il fatto che la costruzione di alloggi è andata in profondità nel 2008 ed è stata lenta a riprendersi. Raymer ha detto solo 860, 000 case e appartamenti sono stati costruiti in tutto lo stato dall'entrata in vigore del codice. Questo è solo il 6% del patrimonio immobiliare dello stato.

Secondo Cal Fire, ben 3 milioni di case si trovano all'interno delle varie "zone di gravità del rischio di incendio" in tutto lo stato. Dave Sapsis, uno scienziato del fuoco selvaggio di Cal Fire, ha detto che non c'è modo di sapere con certezza quante di quelle case sono state costruite prima del 2008, ma crede "è la loro preponderanza, la maggioranza."

La situazione è peggiore nelle zone rurali della California, dove la costruzione di alloggi è in ritardo ma i rischi di incendio sono tra i peggiori dello stato, ha detto Raymer. Dopo il 2008 sono state costruite meno del 3% delle case lungo il percorso del fuoco da campo.

"La maggior parte del nostro inventario che era qui prima dell'incendio è stato (costruito) tra gli anni '40 e '70, " ha detto il consigliere comunale del Paradiso Michael Zuccolillo, un agente immobiliare. "La casa media qui era degli anni '70."

Che lascia migliaia di case a rischio dal prossimo inferno in tutta la California, le loro tegole di legno che aspettano di accendersi.

"Cosa faremo con il patrimonio edilizio esistente che è stato costruito in questi luoghi?" disse Max Moritz, uno specialista di incendi boschivi presso l'UC Santa Barbara. "Per il patrimonio immobiliare esistente che è là fuori, che non è costruito su questi codici, abbiamo un enorme problema di retrofit tra le mani. Hanno vulnerabilità di accensione strutturale che sono integrate nella situazione, sono radicati nel problema."

"L'anello più debole"

I Carrel, ora vive in una casa in affitto a Roseville, progettò la loro casa paradisiaca e si occupò personalmente di gran parte dei lavori interni; sapevano che la casa è stata costruita pensando alla sicurezza antincendio.

"Sapevo che eravamo in mezzo alla foresta, " Oney Carrell ha detto durante una recente visita in Paradise. "Perché non dovresti fare tutto il possibile per farlo durare?"

Ma anche lui è stupito che la loro casa ce l'abbia fatta. Scavalcare uno scarico del patio annerito a pochi metri dal retro della casa, si chiese ad alta voce:"Non so perché si è fermato qui."

È quasi impossibile dire con certezza perché alcune case siano ancora in piedi in Paradiso, mentre altri sono stati rovinati. Il paesaggio ha sicuramente giocato un ruolo; gli esperti del fuoco dicono che le case tamponate dal cosiddetto "spazio difendibile" probabilmente hanno fatto meglio di quelle avvolte da arbusti. La fortuna era un fattore importante, pure, poiché le case sono state senza dubbio risparmiate dai cambiamenti dell'ultimo secondo nel vento.

Tuttavia, dicono gli esperti, L'analisi di McClatchy rafforza la loro convinzione che il codice edilizio antincendio della California possa fare la differenza in un'era di crescente vulnerabilità. Daniel Gorham, un ex pompiere e ricercatore del servizio forestale degli Stati Uniti che lavora per l'Insurance Institute for Business &Home Safety in South Carolina, ha detto che il codice della California sta diventando un modello per altri stati a rischio di incendio.

"La California fa passi da gigante rispetto ad altre parti del paese, " ha detto Gorham. "La California è in prima linea".

Advocates say fire-resistant building materials aren't particularly expensive. A study last fall by Headwater Economics, a consulting firm in Bozeman, Mont., found that "a new home built to wildfire-resistant codes can be constructed for roughly the same cost as a typical home."

But getting Californians to retrofit homes built before 2008 is an enormous task. The state requires property owners in fire zones who replace at least half their roof to install "fire-retardant" materials on the entire roof. Other than that, però, there's nothing forcing Californians to safeguard their existing homes against fire hazards.

A few California cities have taken matters into their own hands. In 2008, the City Council in Big Bear Lake, a community of 5, 200 in San Bernardino County, passed an ordinance declaring wood shake shingle roofs "a severe fire hazard and danger" and ordered homeowners to replace them by 2012. Armed with state and federal grants, it offered cash incentives of up to $4, 500 apiece for new roofs.

Although the grant program has run out, "I can't think of the last time I saw a shake roof in Big Bear, " said Patrick Johnston, the city's chief building official.

Most Californians, però, are on their own when it comes to spending the tens of thousands of dollars needed to replace a roof or install fire-resistant siding. The state offers no financial incentives for fire safety the way it does, say, for earthquakes—homeowners in quake zones can get up to $3, 000 apiece from the state to gird their homes against seismic disaster.

There are signs, però, that the state is beginning to get more serious about retrofitting homes for fire safety.

A law signed last year by former Gov. Jerry Brown requires the state fire marshal to develop a suggested list of "low-cost retrofits" by January 2020. The state would then promote these retrofits in its education and outreach efforts.

California also might start throwing cash at the problem.

A new bill, AB 38, introduced earlier this year by Democratic Assemblyman Jim Wood of Santa Rosa, would create a $1 billion "fire hardened homes revolving loan fund" to help homeowners retrofit their properties.

The issue is personal for Wood, a dentist who spent weeks helping identify victims from the Camp Fire and the wine country fires of October 2017. Although eligibility terms haven't been spelled out, the bill would offer low-interest and no-interest loans to help those who otherwise couldn't pay for new roofs or other safeguards.

"A lot of these small towns are not as well off financially, " he said. "We need to find a way to help them, especially if they're poorer."

The fund might not be nearly enough to go around—not with hundreds of thousands of homes in need of retrofits, and a new roof alone costing $10, 000 or more. "The $1 billion, infatti, that's not enough to rehab every home, " said the Building Industry Association's Raymer. But he said it's "an absolutely excellent way to kick things off."

Wood said state officials would have to figure out a plan for parceling out the money to where it's needed most—probably starting with lower-income areas near forests.

"Obviously we want to affect the areas with the highest risk first, " the assemblyman said. "A lot of these small towns are not as well off financially. We need to find a way to help them, especially if they're poorer."

Mapping 'Severity Zones'

The fire-safe building code had its origins in two significant fires from a generation ago—the Panorama Fire of 1980, which spilled out of the mountains into the city of San Bernardino; and the monstrous Oakland Hills Fire of 1991, which wiped out 2, 500 homes and killed 25 people.

In risposta, the Legislature ordered the Department of Fire Protection and Forestry to start mapping major fire risks in California, in the hinterlands as well as urban areas. The result was a collection of maps of the state's "fire hazard severity zones, " encompassing more than one-third of California's land mass.

Based on factors such as terrain, vegetation and weather patterns, the zones represent Cal Fire's attempt to predict the probability of a fire starting and the likelihood that it could become significant, said Cal Fire's Sapsis.

The maps spawned tighter building standards. The Legislature mandated fire-resistant roofs in these fire-prone areas. Then in 2008 the state laid out a more comprehensive scheme. The California Building Standards Commission rolled out a suite of regulations, known as Chapter 7A, that set strict rules for roofing materials, siding, windows, decks and other elements of a home built in 2008 or later—right down to the minimum specs for the wire mesh that must be installed on attic vents to keep embers out (no more than a quarter-inch of space between the wires).

Experts said the regulations seem to be particularly effective at protecting structures from the types of wildfires that are increasingly common in California, where wind gusts can blow embers a mile or two ahead of the main wall of flames and do some of the worst damage.

"A window breaks, a vent breaks, the fire gets into your home and you've got an interior structure fire, " said Joe Poire, the city of Santa Barbara's fire marshal.

Enforcement of the building code carries a few wrinkles. In the mainly rural areas where Cal Fire is in charge of fire protection, the Chapter 7A code is automatically enforced in any region that Cal Fire has designated as a "severity zone"—moderate, high or very high.

In urban areas that have their own fire departments, the code is generally used only in spots where Cal Fire says the threat is very high. Local governments have the discretion of rejecting the Cal Fire designation, and Sapsis said some city councils have been squeamish about the state's maps because of fears that the Chapter 7A code will inflate construction costs, or for other reasons.

Yet interviews with local officials throughout California by McClatchy indicate that the vast majority of cities and towns go along with Cal Fire's recommendations. Santa Barbara city officials extended the building code to coastal areas that had been overlooked by Cal Fire's mappers. The map omits small portions of Paradise, but the building code is enforced across the entire town, said Paradise public information officer Colette Curtis.

Danger In Santa Rosa, Folsom?

Tuttavia, there are places where local officials are reluctant to impose strict building codes—even where fire has caused catastrophe.

Before Paradise exploded, Santa Rosa's Coffey Park was the poster child for recent California wildfire disasters:Five people died and 1, 321 homes were destroyed by the Tubbs Fire in October 2017.

Coffey Park wasn't subject to California's Chapter 7A building code. It still isn't.

Unlike some areas of Santa Rosa, the neighborhood hasn't been designated a "very high fire hazard" zone by Cal Fire. City officials are OK with that. Although developers rebuilding Coffey Park are being urged to consider fire-resistant materials, city spokeswoman Adriane Mertens said the city doesn't see any reason to impose the 7A code in the neighborhood.

"There were very, very high winds that night, " Mertens said. "There were embers that were blown across the (Highway 101) freeway, across six lanes of freeway, into Coffey Park."

Jack Cohen, a fire scientist in Montana who helped develop the 7A code, said he thinks Santa Rosa is committing "an error in judgment" by rebuilding without the safeguards.

In any event, Cal Fire is updating its fire hazard maps over the next year or so, taking into account more sophisticated data on wind and other climate factors, and Sapsis said spots such as Coffey Park could wind up designated as high-risk areas. Once the maps are done, any region placed inside Cal Fire's "very high fire" zone will have no choice but to comply, under a bill signed into law by Brown last year.

But there will still be ways for cities to skirt the state building code.

Look at Folsom, widely considered one of the most vulnerable places in greater Sacramento to fire. The county's hazard mitigation plan says 44, 000 residents of Folsom are already at "moderate or higher wildfire risk."

Now the suburb is building a development called Folsom Ranch, eventually to be home to 25, 000 persone, on a parcel south of Highway 50.

The development is on land that used to be subject to the strict state building code. Now it isn't.

How did that happen? Years ago, the land was outside Folsom's city limits and Cal Fire was responsible for its safety. Cal Fire's maps put the land in the "moderate" risk zone—a threat level high enough that, under the state's regulations, the fire-safe building code took effect. As it happened, no construction took place during that time, city officials say.

The situation changed when the city annexed the land to forge ahead with Folsom Ranch. Because the land has never been in the state's "very high" risk zone, the city feels comfortable letting Folsom Ranch develop without the Chapter 7A building code.

Fire Chief Felipe Rodriguez said Folsom officials are still open to "the possibility of strengthening, hardening, our future homes." But for now, the city is only requiring homeowners' associations to implement a "vegetation management" plan and install fire-resistant fencing around properties that abut open space areas, Rodriguez said.

Is Folsom courting danger? Rodriguez doesn't think so. The city will build two fire stations in the development and will "be able to suppress a fire during its early stages, " Egli ha detto.

'Sticks In A Fireplace'

The hundreds of thousands of older homes in fire zones aren't just more vulnerable in their own right.

Experts say they spread danger to new homes built to stricter standards.

"One little house built to a new standard, surrounded by a bunch of older stuff, is likely to get swamped, " Sapsis said.

Paradise provided a grim reminder of that problem. The Camp Fire destroyed more than 80 percent of the 4, 100 mobile homes in its path, whether they were built to the new code or not, according to McClatchy's data analysis. That isn't surprising, Sapsis said, given that many of Paradise's mobile homes were jammed alongside one another in mobile home parks.

"They're stacked so close together, they're like sticks in a fireplace, " Sapsis said.

Sapsis and others say the lesson is that strong building codes aren't enough. In particolare, experts say communities must pay more attention to how they lay out their neighborhoods, allowing for firebreaks and enough space between houses.

"In the name of affordable housing, we're moving housing closer and closer to one another, " said Chris Dicus, a forestry and fire expert at Cal Poly, San Luis Obispo. "That serves to have house-to-house-to-house ignition."

The problem isn't limited to densely-packed urban areas. "I live in a rural community, and I have got six feet basically separating me from my neighbor, " said Dicus, who lives outside of Morro Bay.

Inoltre, experts say California is struggling to enforce the state law regarding "defensible space" around properties.

The law requires that property owners maintain as much as 100 feet of defensible space around homes and other buildings in and around "a mountainous area, forest-covered lands, brush-covered lands, grass-covered lands, or land that is covered with flammable material." That means keeping trees and shrubs pruned and spaced far apart. Within five feet of the building, property owners are supposed to remove anything that could catch fire:mulch, plants, woodpiles and so on.

In pratica, però, enforcement of the defensible space law has been spotty at best. Raymer, of the California Building Industry Association, said most property owners don't understand how to maintain their yards. The state doesn't impose penalties for non-compliance, and only a few local governments have chosen to do so, Raymer said.

Legislation could change that. SB 190, by Sen. Bill Dodd, D-Napa, would require the state fire marshal to develop a "model defensible space program, " including penalties, that local governments could adopt.

The problem extends beyond homeowners' property lines. Gov. Gavin Newsom, finding some rare common ground with the Trump administration, is advocating for more aggressive management of forested lands.

A thinned forest northeast of Paradise provided one of the rare victories of the Camp Fire. As the fire raged out of the tiny community of Pulga, it essentially spared the northern part of Magalia. The reason was a series of forest-thinning projects conducted in recent years and overseen by the U.S. Forest Service, Sierra Pacific Industries and the volunteer Butte County Fire Safe Council. The council also worked diligently with area residents to clear brush from their property.

All that work "did exactly what we hoped it would do, " said Calli-Jane DeAnda, executive director of the council, which secured $1 million in grants to remove fuels from forested areas. "This investment of public money is so worth the effort."

The Paradise 'Lab Experiment'

The rebuilding of Paradise means thousands of homes are going to be constructed in the coming years to the stricter standards promulgated by the state in 2008. It represents the single largest test of the effectiveness of the building code.

"That is an absolute lab experiment for us, " Sapsis said.

On the streets of Paradise, anche se, community leaders are taking a more measured view. Zuccolillo, the town councilman, said asphalt roofs and stucco siding might "give us more of a chance" but he doubts they will guarantee Paradise's safety.

"I saw metal buildings, metal and stucco buildings, burn to the ground, " Egli ha detto.

Ancora, there's plenty of evidence, all over Paradise, that the state's building code can protect property.

The other day, Sean Herr pulled into his driveway on the west side of Paradise, where he and his wife Dawn were raising their two young children.

The first thing he did was bring out the ultimate symbol of resiliency:an American flag, the same one that flew on his front porch the day of the Camp Fire.

Like the flag, the house is still standing. The Herrs' home, built in 2010, suffered a bit of scorching and some interior smoke damage—the smoke is bad enough that they're still temporarily living in Chico and aren't certain they'll move back.

Ancora, they marvel at what a close call they had. A Ford Excursion and a boat parked in the front yard, just a few feet from their porch, were destroyed. Five motorcycles locked in a shed behind the house got ruined. Most of their neighborhood is gone.

The Herrs believe their attention to defensible space—the house is mostly encircled in gravel—and the strictness of the building code probably made the difference.

"Our yard and the construction of the house saved it for sure, " Dawn Herr said, gesturing to a small scorch mark by the side of the house. "You can see it tried to catch on fire."

© 2019 The Associated Press. Tutti i diritti riservati.