PROVO — Investigators could be sifting through the ashen remains of the Provo Tabernacle for the cause of last week's fire as early as Tuesday morning.

A construction crew hired by the LDS Church spent Monday tearing down some remnants and removing debris from the fire-ravaged building to make it safer for investigators to search the rubble. Demolition included the remainder of the gabled end of the roof on the west side. 

Investigators spent the day studying old construction and remodeling plans for the more than 100-year-old tabernacle. They're familiarizing themselves with the layout so they have an idea of where to start once they get inside, said Provo Deputy Fire Chief Gary Jolley.

"What they're trying to do is develop a game plan," he said.

Fire Marshal Lynn Schofield also interviewed performers who were rehearsing the night before the blaze broke out to better understand the conditions inside the tabernacle and how things were set up, he said.

"It's been real helpful talking to those people," Jolley said.

Flames tore through the iconic building last Friday morning, gutting the interior. Debris piled 9 feet high covers the floor. The outside brick walls remain standing.

Officials have said once investigators get inside it could be days if not weeks before the cause is determined.

"This is going to be a long processes because it's a large building," Jolley said.