PROVO — Somewhere, buried in 9 feet of debris, lies the key to what caused the fire that stole what some would say is the heart and soul of Provo.

Just one day after an unyielding blaze burned through the historic Provo Tabernacle, emotional firefighters, residents and civic leaders were left with nothing to do but mourn.

"This is an icon," Provo Fire Battalion Chief Tom Augustus said Saturday. "Nothing has so much emotional contact as this with literally everyone in Utah County."

Provo Mayor John Curtis compared the loss to that of losing a loved one "who we have known all our lives and are very close to."

As parts of the building continued to smolder Saturday and billow more smoke, firefighters "devastated" by the fire were buoyed by "the outpouring of food, drinks, people stopping by expressing gratitude, asking questions, even shedding a few tears on the sidewalk with us," said Provo Fire Chief Blair Camp.

"It's been amazing," the chief said.

The cause of the fire and the amount of damage sustained has yet to be officially determined. There is also the question as to what the future of the building will be.

The tabernacle belongs to The Church of Jesus Christ of Latter-day Saints and its fate lies in the hands of church leaders, Curtis said. It may be days and even weeks before they have the information needed to make any decision.

"Past efforts made by the church on other facilities demonstrate their commitment, their care and their ability," the mayor said.

Provo Fire Marshal Lynn Schofield said contractors will go in on Monday to stabilize the building and make it more safe for fire investigators, whom they hope to send in by Wednesday. They will also do some "selective demolition of problem spots," including a V-shaped gable on the western tabernacle wall.

Even then, Schofield said they don't anticipate a report until "well after Christmas," considering the number of witnesses they hope to question and the obstacles they face in finding what may have caused the four-alarm fire.

"The evidence we're looking for is buried very deep and it is very small," he said, noting that 9 feet of debris covers the floors of the large structure.

Investigators are looking at every possible cause of the fire, from electrical issues to light bulbs to arson.

"Everything is on the table," Schofield said.

In the meantime, residents continued to struggle Saturday to come to terms with the damage sustained to the building, which was constructed well over 100 years ago by early Mormon settlers.

"It's just so sad this historic site is gone," Provo resident Jenny Harston said. "The pioneers worked so hard to build it."

Harston and her two daughters were taking photos of the tabernacle.

"Residents in a very real way are feeling the loss in their hearts," Curtis said. "From the minute I arrived, I sensed a grieving process from our city."

A memorial service will be held to honor the tabernacle Sunday at 7 p.m. at Utah Valley University. Following the memorial — where civic leaders will speak about the history and significance of the building — there will be a performance of Lex de Azevedo's "Gloria," which was scheduled to be performed all this weekend in the tabernacle.

A rehearsal of that production was held in the tabernacle until late Thursday night. About 200 singers, musicians and film crew members are among the many people Schofield said he plans to interview.

The fire marshal said Saturday that damage to the tabernacle could easily surpass $1 million. In the late 1800s, it was constructed at a cost of $100,000.

Yet de Azevedo told concertgoers during Friday night's displaced concert that the tabernacle's elaborate pipe organ, which had been housed in the building since the early 1900s, was alone worth more than $1 million.

Schofield also noted Saturday that "hundreds of thousands" of dollars in production equipment and instruments connected to the "Gloria" program were lost in the fire. But that estimate may be low. A KBYU official told an associate the school lost $2 million worth of video and sound equipment just in one production truck that was parked at the tabernacle. And de Azevedo noted that one rented piano alone was valued at more than $100,000.

Barry Rishton, who used to play and tune the tabernacle's organ, said it had a "great sound" that was emphasized by the other features of the building, including its wood floors, stone walls and high ceiling.

"I remember it very vividly," he said. "The sound was beautiful."

He said he hopes to see the tabernacle rebuilt and outfitted, once again, with an organ, though he said its sound could never be replicated.

"Those old pipes had a tonality that was very special," he said. "It was a great instrument. The people in that valley are really going to miss it."

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