The Knox County Courthouse will close at 4:30 p.m. Thursday and remain closed through the weekend after contractors discovered a collapsed sewer line beneath part of the building during an ongoing restroom renovation project.

County officials said engineers determined sections of underground sewer infrastructure beneath the courthouse had fully collapsed, causing erosion of soil beneath a localized portion of the foundation area.

Structural engineers, environmental consultants and representatives from the Galesburg Sanitary District were brought in to evaluate conditions and develop a remediation plan. Officials said engineers determined there is no immediate structural safety hazard, but the repair work requires excavation, underground stabilization and filling portions of the underground void with soil, rock and concrete.

As a precaution, engineers recommended vacating occupied areas directly above the remediation zone during this phase of work.

Knox County Sheriff Jack Harlan and Knox County Board Chairman Jared Hawkinson announced the courthouse will be closed Friday, May 8, with access restricted to remediation personnel only. The courthouse is expected to reopen for normal operations at 8:30 a.m. Monday, May 11.

Officials said additional measures taken since the discovery include multiple rounds of air quality testing and ground-penetrating radar scans to confirm no additional underground voids exist beneath the courthouse floor.

Temporary restroom trailer units remain available on the west side of the courthouse for employees and visitors and are accessible through coordination with the Sheriff’s Office.

Anyone with court appearances or court-related business scheduled for Friday should contact the Knox County Circuit Clerk’s Office for additional information.

County officials said updates on construction schedules and courthouse operations will continue to be released as work progresses.