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Federal investigators on Thursday shared updates on their investigation into the cause of the catastrophic Condominium collapse in 2021 in Surfside, Florida, which provides key information about the factors that may have led to the deaths of 98 people under a mountain of rubble.
Researchers have identified hundreds of possible failure points in the building, ultimately narrowing down about two dozen hypotheses for what might have triggered the collapse, National Institute of Standards and Technology officials said in a presentation about their progress.
The investigation has revealed that the building’s pool deck, located at ground level above an underground parking garage, collapsed at least four minutes before the rest of the building, which it previously confirmed. witness reports. Possible structural failures in the pool deck or in the columns supporting the tower are among the major issues now being analyzed as teams investigate the cause of the disaster, investigators said.
Part of The Champlain Towers South building collapsed in the pre-dawn hours of June 24, 2021, turning what was once a thriving residential building into a devastating scene as residents were crushed or trapped under a massive pile of twisted metal and concrete.
It took search and recovery teams approximately a month to find and identify the 98 victims, who ranged in age from 1 to 92 years old. The tragedy affected families around the world, including Argentina, Paraguay and Colombia. In some cases, entire families were murdered.
The tragedy may have been decades in the making. Investigators have determined that the integrity of Champlain Towers was likely compromised when it was being built in the 1970s, noting that the design and construction of some portions did not meet standard building code requirements at the time.
But the search for answers is far from over, as investigators must continue to meticulously examine the evidence and rule out the long list of possible scenarios. Its final findings are expected to be published in a report next year.
The agency investigates major building failures and disasters, including the World Trade Center at 911, but does not determine criminal culpability. Instead, it may recommend changes to building codes to improve future safety standards.
CNN has sought comment from Surfside city officials.
These are the key takeaways from Thursday’s research update.
When construction of Champlain Towers finished in 1981, parts of its structural design did not meet the required building code, particularly in the pool deck and tower columns, investigators said in their presentation.
“We discovered several locations where construction did not meet the requirements of the plans, the building code or common practice,” said James Harris, one of the probe’s project leaders.
Deficiencies were found in the placement of the building’s steel reinforcements, concrete alignment and strength of the columns and floor concrete, according to the presentation. Officials noted that several areas of the pool deck had “serious” strength deficiencies.
In the months before the collapse, the building was also facing major structural repairs. Condo association president Jean Wodnicki outlined some of the problems in a letter to homeowners in April 2021, noting that “concrete deterioration is accelerating.”
At the time of the collapse, the condominium association had approved an appraisal detailing $15 million worth of repairs, a process they began more than two years after receiving a report of “major structural damage” to the building, CNN reported.
Before chaos erupted, one resident reported that he was awakened by a family member concerned about “metallic noises” reverberating through the building, and moments later saw the pool deck fall into the underground garage below, he said. Emel Ganapati, who is co-leading the evidence collection efforts for the investigation.
According to investigators, the slab supporting the pool deck collapsed more than four minutes before the tower collapsed. The connection between the slab and its support columns may have failed, causing the slab to fall into the garage, they said.
“There were indications of severe damage to the pool deck at least three weeks before the collapse,” investigators said in the presentation.
Residents had reported hearing “banging” and “hammering” sounds before the incident that may indicate that the slab reinforcement had fractured, he said. The evidence also revealed that the slab had collapsed, exposed to water and corroded in some areas.
Over time, the planters decorating the pool deck also became heavy with more fill and paving than originally designed, increasing the weight load on the slab, according to the presentation.
Together, all of these deficiencies created “critically low margins against failure” at the time of the collapse, he said.
Still, the researchers noted, “while there is strong evidence that the collapse began on the pool deck, we have not yet ruled out an onset of failure somewhere in the tower” that may have occurred before the pool collapse. pool deck.
Failure of the tower columns is also a possibility.
Investigators said they have identified several scenarios in which the columns supporting the south edge of the tower could have failed, forcing their load to be distributed elsewhere and causing the collapse.
Signs of impending disaster can be seen in video footage showing “severe structural movements” in the tower before the fall, and roars and booms could be heard in one of the upper floor hallways before the floor began to sink and deform, according to researchers.
The initial structural failures that caused the eastern portion of the collapse likely occurred below the third floor, investigators said, noting that video footage shows the building’s façade moving “uniformly downward” during the fall.
The tower’s columns could have been compromised in several ways, including corrosion, exposure to water and poor installation, the presentation noted.
There are still dozens of hypotheses
Although researchers said they have identified strong evidence supporting the most likely causes of the collapse, they have yet to meticulously rule out dozens of other hypotheses through extensive analysis and testing of the evidence.
Among the other possible, but less likely, causes were that the foundations were laid unevenly or were built on topography that developed sinkholes or other weaknesses, officials said.
Once the investigation is complete, the National Institute of Standards and Technology plans to publish a multi-volume final report on its findings, as well as an online presentation tailored to the public by fall 2025, he said.
“There are millions of high-rise condominium units in Florida alone, many of them older structures near the ocean,” their website says. “While a NIST investigation aims to identify the cause of the Champlain Towers South collapse, it could also uncover potential problems at other similar buildings nearby and across the country.”
The report can also provide much-needed answers to the victims’ families, who have seen security legislation and important legal agreements but I have been waiting years to clarify why the tragedy occurred in the first place.
CNN’s Jamiel Lynch, Nouran Salahieh and Joe Sutton contributed to this report.
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