The cause of the fire that destroyed Sebastopol's Frizelle Enos Feeds remained a mystery Sunday, and many heartsick customers were waiting to learn what the future holds for the landmark west Sonoma County business.

"I'm hoping they'll rebuild, and they'll do it as quickly as possible," said Mayor Michael Kyes, whose view was echoed by many former customers. The feed store, where Kyes said he regularly shops, was "sort of iconic of Sebastopol."

On Saturday evening, fire ripped through the building, an anchor on the eastern edge of downtown for 80 years.

The blaze apparently started in hay bales in the back, fire officials said. The cause remains under investigation, but the most likely possibility was the fire had a human origin, said Assistant Fire Chief Mike Reeser.

On Sunday morning, both the building and business owners surveyed the wreckage, Reeser said.

The building owner, Tennyson Tucker, later said that contractors had told him the entire structure must be leveled before anything can be rebuilt there. He said he might be willing to rebuild, but he first needs to learn what value his insurance company will put on the damaged building.

"I think everybody in Sebastopol and the customers would like to see it rebuilt," Tucker said. "Hopefully, the building department will work with us so we don't get delayed."

Tucker had long owned the business, the longest-running in Sebastopol, until he sold it to a business partnership nearly three years ago. The partners all declined comment Saturday at the fire and have yet to publicly state their intentions.

But Reeser said the partners told him Sunday they would like to find a temporary site and quickly reopen for business, possibly nearby on Petaluma Avenue at the proposed location for a CVS store.

That idea was welcomed by customer Sarah Flood Davis, a Sebastopol resident who first went to the store at age 4 and as an adult has taken her two children shopping there.

"It's a wonderful place," she said, standing next to the yellow police tape strung across the driveway.

Another customer, Leisa Lambert of Sebastopol, said she had planned to bring her 5-month-old puppy to the store Sunday for shots offered by a regluar mobile pet clinic that sets up shop in the parking lot. She expressed hope that the store would rise again.

"They have everything there," Lambert said.

The business, known as Frizelle Enos Feeds, Seeds N'Country Needs, sold not only feed and pet goods but also woodstoves, clothing and gifts. A few former customers said they did Christmas shopping there.

Fire crews worked early into Sunday morning "cooling down any hot spots and making sure things stayed out," Reeser said.

An excavator and bulldozer crew stayed at the Petaluma Avenue site until almost 3 a.m., removing hay bales and anything else that might smolder, Reeser said.

A ladder truck was all that remained at the site by 9 a.m. Sunday at the shell of the west county's largest emporium for backyard farmers, pet owners and other country residents.

Firefighters returned briefly Sunday afternoon to the burned-out block walls with the red-and-white checkerboard band across the top. Passersby had spotted "a little whiff of smoke" about 4p.m., and a fire engine rolled up so that crew members could spray down more retardant foam, Reeser said.

The fire damage was so extensive, resulting in a total loss, that investigators may unable to pinpoint an ignition source of the blaze, Reeser said.

There was no electrical circuitry or gas source near the fire's origin, he said.

Some observers suggested the fire could have started by spontaneous combustion in the hay. While unable to rule out such a possibility, Reeser said "it's not very likely" because spontaneous combustion requires moisture and the bales were reportedly dry.

That leaves human origin — whether accidental or intentional — as the most likely possibility, he said.

Investigators are seeking witnesses who might have seen what happened.

"That's the only way we're going to be able to determine what happened," Reeser said.