Likely that pool deck took the building down with it
Years after the tragic 2021 Surfside condo collapse that killed 98 people, a new report from the National Institute of Standards and Technology (NIST) is reinforcing preliminary findings (and videos) that the catastrophic failure likely started in the adjacent pool deck – not in the building itself. Earlier this month, investigative lead Judith Mitrani-Reiser and co-lead Glenn Bell presented the update to the National Construction Safety Team (NCST) Advisory Committee, highlighting strides in the failure analysis. The process has been lengthy and involves reconstructing the state of the building before collapse using a wide range of sources like photographs, maintenance records, and eyewitness accounts. The graphic below displays much of the collected information, including the location of cracks and construction joints that have been vital in the ongoing investigation.
The NIST National Construction Safety Team analyzed photographs, building maintenance records, and eyewitness reports to develop this graphic showing where cracks had been identified in the first-floor slab in the months and years before the 2021 partial collapse of Champlain Towers South. The cracks are noted in turquoise, while construction joints (where concrete slabs meet) that are of interest to the investigation are shown in pink. Note the concentration of cracks in the street-level parking and pool decks. Credit: Miami-Dade County Open Data Hub/NIST
Researchers have been refining analyses of steel corrosion, concrete shrinkage, and improperly built construction joints to determine how big of a role each played in the collapse of the Champlain Towers South condominium building. These variables are then funneled into large-scale structural testing and other computer models which can simulate the collapse and show its progression from the pool deck into the main towers.
Champlain Towers South Condominium, Sunrise, FL
The culmination of these efforts? According to Bell, they “indicate that it is more likely that the failure started in a pool deck slab-column connection,” corroborated by the fact that the pool deck began collapsing at least seven minutes before the tower. Mitrani-Reiser highlighted indications that the building was in distress in the weeks before the collapse, concentrated in a small area of the pool deck and street-level parking deck. These include reported cracks in the planter wall, a sliding glass door that came off its frame, and vertical shifting of a gate, rendering it inoperable. Leakages in the ceiling of the garage near the pool were also documented a day before the collapse, which worsened rapidly in the hours before tragedy struck.
Local and federal task force crews continued to work day and night at the collapse site of the Champlain Towers South in Surfside. As of July 10, 2021, 11,595 cubic yards of rubble had been removed from the site. Courtesy, Miami-Dade Fire Rescue
The NIST team hopes to have all the technical work done by year’s end, which will include drafts of a summary report and six subject-focused technical reports. It is engaging with key stakeholder groups in the building design, construction, inspection, evaluation and maintenance fields to share these preliminary analysis results and gather information that will result in technical and policy recommendations. “This tragic event has revealed flaws in our systems, and quality is at the heart of it,” said Mitrani-Reiser. She said the next public update will be next spring.
As we know, the Surfside collapse shook up the condominium landscape across the Sunshine State, first through sweeping legislative reforms in building safety and maintenance reserve funding, then an easing in the timetable of those reforms this past May. The tragedy also brought the now infamous Fannie Mae blacklist to light, as many condo owners tried to jump ship and were surprised to find that lenders wouldn’t offer mortgages to would-be buyers because their building didn’t meet federal standards. More than 2,800 Florida properties are on the list.
LMA Newsletter of 9-22-25
