NIST Report to Congress Provides Update on Champlain Towers South Investigation

The National Institute of Standards and Technology (NIST) has submitted to Congress an update on its investigation into the partial collapse of the Champlain Towers South condominium in Surfside, Florida. The update is included in a report submitted to Congress on NIST’s activities under the National Construction Safety Team (NCST) Act. 

The report notes that the team has completed all experimental work on the physical evidence from the building’s structural elements. This includes mechanical testing of concrete cores and steel reinforcing bars, and measurements of slab, beam and column cross sections. The team also completed a study of historical wind loads on the building, as well as 3D simulations of the subsurface conditions beneath the building site.

In a video released today, investigation lead Judith Mitrani-Reiser and associate lead Glenn Bell, explain how the work completed so far is informing their understanding of what caused the collapse, and how it could make buildings across the U.S. safer.

Champlain Tower South Collapse Investigation | 2025 Update

As described in the report to Congress, the team is now focused on its remaining technical work. This includes completion of full-scale tests of replicas of Champlain Towers South building components at the University of Minnesota and the University of Washington, which began in 2024. The University of Washington tests include measuring the impact of corrosion of the concrete’s steel reinforcement. This work provides critical input for the computer models of the collapse that will help determine the probable initiation and progression of the partial collapse and its technical causes.

The team has begun the final phase of interviews with those who have knowledge of the building on the night it collapsed and before. Team members continue to conduct archival research of records and tests of subsurface materials. 

As detailed in the report, the investigation relies on many contracts and agreements to bring in special expertise, equipment and facilities. Standard federal timelines for acquisition directly affect the pace at which the investigation can proceed, as shared in the March 7, 2024, public NCST Advisory Committee meeting. NIST continues to seek solutions so that the investigation can be completed as quickly as possible. 

The NCST Advisory Committee released its own report to Congress in December 2024. In that report, committee members commended the NIST team for its “diligence and efficiency,” “dedication to ethical communication,” and “groundbreaking work.” The committee also applauded the team for its rigorous testing of material evidence and full-scale replicas of building components and encouraged NIST to continue to incorporate the variability of measured material properties in its future work.

NIST plans to provide its next technical presentation on the investigation in early June 2025.