Construction crews had placed "insufficient support" beneath part of an upper floor that collapsed during renovations on the 124-year-old federal courthouse in Savannah, according to the government agency overseeing the project.

Three construction workers were injured April 11 when a section of the courthouse's third floor gave out, causing them to fall to the floor below.

The General Services Administration said in a statement Tuesday that the $75 million renovation project remains paused as crews clear debris and stabilize the area where the collapse occurred.

"GSA's initial evaluations indicate that the immediate failure was due to insufficient support beneath the third floor of a section of the building, and not the result of systemic structural issues," the agency's statement said. "A full investigation of the building is still ongoing."

The Tomochichi Federal Building and U.S. Courthouse opened in 1899 on Wright Square in the heart of Savannah's downtown historic district. Construction work inside the building has been ongoing for more than a year and is scheduled for completion in 2024.

No courthouse personnel were inside when the collapse occurred.

Brasfield & Gorrie, the general contractor hired to upgrade the courthouse, said in a statement that the three injured workers "are doing well and expected to make a full recovery."

Tags: Georgia  Atlanta  Savannah