“It’s apocalyptic in our little town,” Mr. Wellema said, likening Altadena after the fire to the ruins of ancient Rome.

In a phone interview, the Wellemas, with their children playing out of earshot (they hadn’t yet mustered the strength to tell them about the fate of the store), vacillated between resolve and shock. They spoke of their store in the present tense, then their voices caught as they remembered that their beloved boutique was no more.

“We built it brick by brick,” Mr. Wellema, 32, said of the shop.

Mr. Wellema constructed his hats in the store, which also included a “mini museum” of hat making.Credit…Cody Wellema

The signage on the shop’s front window was hand-lettered by Derek McDonald of Golden West Sign Arts.Credit…Cody Wellema

A native of Colorado, Mr. Wellema grew up in Southern California and became enamored by hat making as a young adult. To him, there was something so rugged, so American about a cowboy hat. “It was a dying trade in America, and I wanted to do my best to keep it alive,” he said.

In his early 20s, he worked at an existing hat-making business in Santa Barbara. Then he ventured out on his own, starting the Wellema Hat Company in Santa Barbara before relocating to Altadena almost a decade ago. The tidy boutique, perched in Los Angeles’s northern foothills, was less than 1,000 square feet, though the couple diverged on how much less.

It required some folly to open a hat store in the mid-2010s. “People don’t wear hats like they did in the ’30s,” Mr. Wellema said. Early on, visitors would pop into the store and ask him, kindly, yet with bafflement in their voices: “Why are you here? Who is your customer?”

The customers turned out to be ranchers (yes, those still exist on the fringes of Los Angeles), fashionable shoppers smitten by the company’s curvaceous felt hat, and costume designers for Western shows. The actor John C. Reilly was a customer, and the store had a number of clients with cancer, who bought hats to block the California sun or cloak hair loss from treatment.

The assured look of Mr. Wellema’s hats, which he constructed inside the shop, grabbed shoppers. Their brims protruded proudly, their crowns were pinched as if pre-broken in. Wellema fedoras called to mind Al Capone. The cowboy hats were pure Marlboro Man.

In time, the Wellema Hat Company became a destination for anyone who appreciated a jaunty hat or just a classic product made right.

“Cody represented this sort of reverence for relics of the golden age of California that still lived on in Altadena and Pasadena,” said Nico Lazaro, a freelance writer and Angeleno who befriended Mr. Wellema. “The shop was one of those rare places that felt both of a time and still relevant today.”

Cody and Shelby Wellema, with their three children, evacuated from their home near the store on Wednesday.Credit…via Cody Wellema

For Ethan M. Wong, the store wasn’t just a place to shop, but to observe. “Every time I visited, I couldn’t help but photograph whatever Cody was working on,” said Mr. Wong, a writer and podcaster who owns three of Mr. Wellema’s saucerlike fedoras.

Shelby Wellema said that business seemed to be taking off in recent months. “Our local walk-in traffic had increased so much,” she said. Mr. Wellema had a theory: The TV show “Yellowstone” had convinced urbanites they could pull off a cowboy hat.

“The Western genre is having a moment,” he said.

His favorite shoppers, though, were those who truly wore his hats, the ones who would come back with dirt marks and gashes all over their $800 Wellema creations.

The couple never took a loan and said that any money made went back into the shop. “Whenever we had $500, a grand, lying around, I was like, ‘OK, I can finally commission this woodworker to build a shelf that I want,’” said Mr. Wellema, who recalled spending his 24th birthday laying flooring in the space.

It was only in recent months that he felt the shop had reached its final form. A corner of the store held vintage clothes. A workbench sat in the middle of the store. A glass case held Mr. Wellema’s “mini museum” of hat making, packed with aged hat brushes, matchbooks and advertising artifacts from companies like Stetson. The swooping signage on the shop’s front window was hand-lettered by Derek McDonald of Golden West Sign Arts. On the walls hung work by Edward Borein, a Western painter who inspired Mr. Wellema’s wide-brimmed hats.

“It was everything I’d ever wanted,” Mr. Wellema said. In November, the family hosted a party at the shop to celebrate 10 years in business.

It’s nearly all gone now. On Tuesday evening, the fire was visible in the hills outside Altadena. “In our hearts we just didn’t think it was going to get into the streets,” Mr. Wellema said. He never thought to grab any of his inventory or tools.

The building where Wellema Hat Company was based.Credit…Mark Abramson for The New York Times

In the immediate haze after the destruction, the Wellemas weren’t certain what to do next. They were fortunate to have had insurance on the shop. A friend initiated a GoFundMe campaign for the family, which had raised more than $50,000 as of Friday afternoon.

But Mr. Wellema was also wondering if the fire was a sign. He loved hat making, but maybe it was better suited as a hobby. He could certainly make more money doing something else.

Really, though, the prospect of building a new space, brick by brick, felt daunting.

“We have to be present,” Ms. Wellema said, referring to the tasks ahead: taking care of their children, returning to their as-yet-still-standing home.

“I’m not sure how much of the past is going to come with us in the future,” she said.