In the weeks following the June 24, 2021, partial collapse of the Champlain Towers South condominium in Surfside, Florida, NIST National Construction Safety Team members conducted remote sensing of the site using lidar technology, which sends out rapid pulses of light and records the reflections to create a spatial map of individual points reflected from surfaces on the ground. This image was captured on July 14, 2021, and provides important information on the post-collapse geometry of building components. Red points represent data on the south basement wall, and yellow points represent data on the privacy wall above.
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NIST
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
Lead investigators Judy Mitrani-Reiser and Glen Bell give a summary of this year’s progress regarding the NCST investigation into the partial collapse of the Champlain Towers South building.
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 University of Minnesota’s Multi-Axial Subassemblage Testing, or MAST, Laboratory built full-scale replicas of building components from the Champlain Towers South building. In this photo, forces are exerted on a replica that combines concrete slabs, columns and a beam.
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NIST
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.
A replica of a reinforced concrete column from the Champlain Towers South building is tested to failure at the University of Washington’s Large-Scale Structural Engineering Testing Laboratory, or SETL. The test apparatus pushes down on the column, applying compression forces along its axis, to provide information on its strength.
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NIST
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. To date, the investigation has included:Analysis of more than 300 potential structural failure points using 25 hypotheses for failure.Review of 20,000 records to establish the building’s history and precollapse conditions.Receipt of 10s of thousands of additional civil litigation records since March 2024.Archival research review of about 60 gigabytes of data.Interviews with 58 individuals, with 92 more interviews and 10 focus groups planned.Structural materials testing on more than 1,000 concrete and reinforcement samples extracted from the building.Geotechnical materials testing completed or underway on 108 soil, rock, foundation and groundwater samples.
