A lot of things about the Thomas Fire surprised veteran Ventura County firefighter Steve Kaufmann.

The fact that it burned 70 square miles in 12 hours. The fact that it nearly incinerated City Hall in downtown Ventura. But perhaps the most shocking to him was that by daybreak on the first full day of the fire, more than 150 homes had been destroyed.

“We don’t normally see major structure devastation on our wildland fires,” he said.

Ventura County has long been known for its strict enforcement of fire protection rules. So it's surprising to Kaufmann and other fire officials that most of the roughly thousand structures that have burned so far in the Thomas Fire have been within its borders.

Since 2001, Ventura County has experienced just a single wildfire that burned more than 18 homes, according to data from the California Department of Forestry and Fire Protection. (It was the Simi Fire, which burned during the epic 2003 wildfire season.)

Los Angeles, Riverside, San Diego and San Bernardino counties all had multiple fires that were more destructive during that same period.

Under California law, residents in areas of high wildfire risk have to maintain 100 feet of clearing around their homes. It's what's known as "defensible space."

But counties have a lot of discretion on how to enforce the law.

In Ventura County, if you don’t clear your brush, officials will fine you $1,658 (it goes up to $1,800 in 2018). They’ll also do the yard work themselves and then bill you for the cost.

Bob Roper, the former fire chief of Ventura County who retired in 2012, said numerous fire officials have called to ask him what they can learn from Ventura’s approach. When he tells them about the high fines, “They say, thanks for the information, but if I tried that in my jurisdiction, we’d be shot.”

Indeed, Ventura County is much more aggressive than most of its neighbors. San Bernardino charges only $100 for failing to clear brush. And Orange County doesn’t have the authority to remove brush on private property at all.

But in the back of Roper’s mind, he always knew that one out of control, wind-blown wildfire could upend his county’s track record of success. Because in those situations, even people who have done everything right can lose their homes.

To show me what he meant, he invited me up to Ojai for a drive.

It was Day 10 of the Thomas Fire, Dec. 13, and the Ojai Valley looked the way I imagine a smoggy Los Angeles did in the 1960s. The sun was a blood orange, and the mountains were a gradient of hazy pastels. The smoke got worse over the course of the day, and after a few hours of driving around, I felt nauseous.

As we climbed into the Upper Ojai Valley, most of the houses we saw along Highway 150 had burned. I saw the charred skeletons of stationary bicycles and the rims of cars melted into silvery puddles. As we pulled into the ash-speckled driveway of another destroyed home, Roper told me the residents had done a great job clearing brush from around their house.

“It happened to be when the wind blows hard enough, you end up with what we call a firestorm,” he said.

This is the face of the Thomas Fire, and it has raised a question across Ventura County: Are its policies actually doing enough to protect homes?

Max Moritz says no. He's a wildfire expert with the UC Cooperative Extension in Santa Barbara.

“Defensible space has a very specific use. It’s to provide a place for firefighters to do their work. It doesn’t actually necessarily in and of itself protect the home from ignition,” he said. “We also have to think of the structure itself. What if nobody is there to defend it?”

Most houses that burn in a wildfire ignite not from a wall of fire, but from windblown embers that can travel up to 4 miles. That means fireproofing a home really depends on how it's built. If a hot ember lands on the roof or deck, will it catch? Can embers blow into attic vents or crawl spaces? Are gutters cleared out, or full of pine needles?

California law requires all new houses in the highest-risk wildfire zones to be built using fire-resistant materials. But there are many older homes in these areas that aren’t required to meet the code unless they're renovated.

“Modern building codes are great for new construction,” said Roper. “But the majority of the homes in the wildfire-prone area are already built.”

For Richard Halsey, director of the Chaparral Institute, the problem isn’t just what the houses are made of, but where they’re built. He believes elected officials who permit construction in fire-prone areas should be held liable when they burn down.

“We cannot keep putting people out in dangerous conditions, like we’re doing, we just can’t,” he told KPCC’s Take Two. “I know there’s a housing crisis, but we’re going to have a mortality crisis if we keep doing this.”

But Roper thinks even the strictest policies in the world won’t stop every firestorm. In 70 mph winds, the most fireproof homes can burn.

“Sometimes Mother Nature is more powerful than us,” he said, as we drove down from the Upper Ojai Valley in thickening smoke. “We can’t win every fight."