Collapsed tower at Surfside had 'severe flaws' in pool deck, researchers say

In a meeting on Thursday, the investigators in charge of revealing why the Champlain Towers South collapsed showed preliminary progress on their inquiries. They point to failures in the pool deck, but are still determining if this is one or part of the causes of one of the worst tragedies in the United States in years in a residential building. Read our special 'Surfside: a prolonged trauma with no lessons learned'.

The building that collapsed in June 2021 in Surfside, Florida, had "severe strength failures" in the floor of the pool deck, as well as building code violations, investigators explained Thursday at a meeting of the National Building Committee. Seguras from the National Institute of Standards and Technology (NIST), in charge of the investigations.

"Under the conditions that we believe were present at the time of the collapse, there was a very low margin of protection in parts of the structure," Glenn R. Bell, the NIST principal investigator for the case, said in his statement of preliminary findings. Champlain Towers South. "Very low in some cases," he specified, noting that it could be a combination of multiple factors.

In his presentation, he began with the floor design for the Champlain Towers South pool: he explained that from the start, the structure was not strong enough in and between many of its supporting columns, among other things, due to the distance between them. . Bell said the problem was severe at various points on the rig.

He explained that the steel reinforcement in the pool deck slabs was buried deeper into the concrete than intended in the initial designs. In addition, planters were added to the north of the pool platform that were not in the original design of the tower, built in 1981. Showing images taken with Google Earth, he explained that they were heavy and tall — even three stories high. height—which added weight to a system already under stress.

Bell noted that the structure was subjected to another additional load of weight added over time in a pool deck renovation: a layer of sand and a layer of waterproofing. "This weight also reduced the margin of failure of the structure," he said.

He said that they also found signs of deterioration and corrosion "of different degrees" in the reinforcing rods of the platform. "This reduces or compromises the strength of the bars." Bell explained that this particular problem will be further studied in the coming months of research to determine the distribution of the level of corrosion that the Champlain Towers South pool structure had and how it could have contributed to the collapse.

The engineer, an expert in structural safety, assured that the western area of the pool platform already showed signs of "severe stress", such as cracks, even days before the collapse: "This failure is consistent with a large deviation of the slab, is consistent with our findings that the structure had little margin of safety."

The collapse of the Champlain Towers South has been listed as one of the worst tragedies the United States has recorded in years in a residential building. 98 people died. Since it happened, concerns about a failure in the pool deck have been present, not only because of the suspicions of residents but also because of reports from inspectors who have evaluated the structure on several occasions. The advance given by NIST this Thursday shows the first hypotheses about the problems of the building after its abrupt collapse.

NIST researchers still have more than a year of investigation to go. The presentation of the final report on what caused the collapse of this tower is scheduled for May 2025. It will be accompanied by recommendations on possible changes in building codes in the United States and the world, and he said that it will show with animations what led to the fall from Champlain Towers South.

The results will include interviews with witnesses, investigations into the condition of the structure before the collapse, computerized tests on the remains of the building.

"We are still exploring a number of potential causes," Bell warned, assuring that this is one of the "most complex and challenging" investigations that NIST has undertaken. He specified that they are still evaluating what led the tower to collapse abruptly on June 24, 2021: "We may find a specific event or a gradual destruction that took place for a long time."

After the Champlain Towers South collapsed, scores of details emerged about the flaws in its structure. The firm Morabito Consultants, for example, had alerted in April 2018 about violations in the pool and parking area. They found peeling paint on the garage ceiling, excess water on the pavement, possibly from leaks caused by a sprinkler. Months after that inspection, they insisted that the garage structure showed "signs of failure and fatigue," with "abundant cracking" in the columns, beams, and walls. They then warned that repairs should be made quickly in areas where the concrete was deteriorated.

The company also explained that poor repairs made to the pool deck —which it is unknown if they were those required by the city of Surfside in March— generated new cracks over those that had been fixed in that area and worsened water seepage into the pool. the underground parking that, they warned, would worsen if the relevant repairs are not made.