A portion of a historic building at 89 N. Washington St. in downtown Sonora where one of the outside walls collapsed earlier this month will be demolished next week.

The co-owner of the building, Joseph Gee, has hired local contractor Ted Radetich to handle the demolition. North Stewart Street between Elkin and Dodge streets is scheduled to be closed from 8 a.m. to 5 p.m. Monday through Friday to accommodate the work.

Kim Campbell, community development specialist, said residents who live on the portion of North Stewart Street will be detoured around the work so they can enter and exit their driveways.

There will also be no parking on that portion of the street during the project hours.

The building was posted as unsafe to occupy by City Building Inspector Daren Wardell after the stacked rock wall on the south side crumbled on April 1, less than two weeks after a heavy rainstorm on March 22.

Wardell has said the building owners had been in contact with the city since January about bulging that led to concerns about the wall’s structural integrity. He did not have an exact determination about what caused the wall to collapse.

A tenant who lived in an apartment on the same side as the wall that collapsed had moved out due to safety concerns prior to the wall’s collapse. Tenants in two other apartments were forced to move out after the building was deemed unsafe to occupy by the city following the collapse.

Gee, a Sacramento college professor who purchased the building with his wife in 2015 as an investment, said he was told by Wardell that it was best to have the building demolished as quickly as possible for safety’s sake.

“It was actually a requirement put forward to me by the building inspector,” he said. “That why I authorized the contractor to start next Monday.”

Gee declined to go into detail about his plans for the building. He said his insurance company cited a number of exclusions in his policy on why the damage is not covered.

He didn’t know when the section of the building that collapsed was constructed, but the stacked-rock style of construction is known to date back to the days of the Gold Rush in the 1850s.

“That kind of construction is pretty common in Sonora and I didn’t expect something like this would happen,” Gee said. “I thought it was solidly built with granite rocks as a foundation, so it was a surprise to me.”

Wardell has said a number of other historic buildings in the downtown area also have stacked rock walls, though he doesn’t know exactly how many because a survey hasn’t been conducted.

Contact Alex MacLean at amaclean@uniondemocrat.com or (209) 588-4530.