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On Thursday, April 10, three members of the National Institute of Standards and Technology’s (NIST’s) National Construction Safety Team (NCST) investigating the June 2021 partial collapse of the Champlain Towers South building in Surfside, Florida, shared technical details of the investigation’s progress with members of the structural engineering professional community. This outreach will help ensure that the team’s findings and recommendations lead to improvements to codes, standards and practices that can prevent similar tragedies from occurring in the future.
Investigative lead Judith Mitrani-Reiser gave the technical presentation along with investigative co-lead Glenn Bell and Jim Harris, co-lead of the investigation’s Building and Code History Project. The presentation took place at Structures Congress 2025, an annual event of the Structural Engineering Institute of the American Society of Civil Engineers, held this year in Phoenix. While the three experts did not provide new findings, they did offer new technical details from the evidence analysis and testing that supported the preliminary findings NIST released in earlier public presentations.
The 2002 NCST Act authorizes NIST to conduct investigations of building failures to determine the technical cause or causes and to recommend ways to make buildings safer.
“We want to make sure the structural engineering community understands how we tested our collapse hypotheses and arrived at our preliminary findings because these are the people who will help to develop and implement improvements to codes, standards and practices that can help save lives,” said Mitrani-Reiser.
Mitrani-Reiser, Bell and Harris explained the team’s systematic approach to analyzing its hypotheses of what caused the building to fail on June 24, 2021. This effort has involved the collection, examination and testing of physical evidence extracted from the collapse site; collection and analysis of documents and imagery; materials and geotechnical analysis and testing; interviews and focus groups with eyewitnesses and other stakeholders; reconstruction of the condition of the structure at the time of collapse; laboratory testing of full-scale replicas of components of the building; and advanced computer simulations of the collapse initiation and progression.
“The work we have been doing is thorough and detailed, so that we can understand as much as we can about the conditions that led to this terrible tragedy,” said Bell. “We are committed to working with the engineering and construction community, including standards development organizations, to ensure our work is applied to making buildings safer.”
The team is nearly done testing full-scale replicas of building components at the University of Washington and the University of Minnesota. The replicas were built using information the investigation has revealed about the building’s design and construction, the properties of its materials, and the forces acting on it.
In his portion of the presentation, Harris offered an overview of the potential implications of the investigation’s findings for building design, construction and maintenance.
In a new behind-the-scenes video, Harris explained that the detailed testing will lead to “improved practices for assessing the deterioration and effect of that deterioration on the safety of reinforced concrete buildings.”
The investigation team plans to provide its next technical presentation in June 2025.