Preliminary report released on Surfside condo collapse
MIAMI - An investigation by the U.S. Department of Commerce's National Institute of Standards and Technology (NIST) continues to point to the pool deck as the cause of the Champlain Towers South collapse in Surfside.
The federal agency in charge of figuring out the cause of the collapse just wrapped up its detailed update on its nearly three-year search for what happened on June 24, 2021.
Thursday's meeting focused on design defects in construction and a lack of meeting safety standards, not just the ones currently in place, but those in effect back in 1979 when Champlain Towers was first being built.
Investigators said that it is clear that the design of the pool deck and tower did not meet strength and other requirements of that time, leading to what we saw happen more than 40 years later.
"We have very, we think, conclusive evidence now that the pool deck collapsed before the tower did in a gross manner," said Glenn Bell, Team Associate Lead, Champlain Towers South NCST NIST.
Investigators have long focused on the pool deck, which is strongly believed to be the starting point of the Surfside collapse.
But the question remains: Why did it collapse?
"Several columns have moderate strength deficiencies and design strength does not comply with the original codes and standards," added Fahim Sadek, Project Leader, Champlain Towers South NCST NIST.
To answer that question, investigators are looking at everything. This includes the columns, concrete mixtures, corrosion, the building's foundation, and the effects of vibrations from construction from neighboring buildings.
"Hundreds of possible failure initiation points in the structural and geotechnical elements," added Bell.
It was narrowed down to about two dozen failure hypotheses, with one of the most likely scenarios being the pool deck slab-column connections.
"Protection the concrete provides rebar is compromised by cracking... resulting in corrosion," said Scott Jones, another project leader for NCST NIST, pointing out a history of water leaking into the garage and around the pool.
Investigators also believe the columns along the south edge of the tower are another likely initiation point for the collapse. Still, everything they have discovered and reported so far is subject to change as this investigation progresses.
"The whole goal from this investigation is to learn from it and bring about improvement in codes and changes in practice to minimize the chance that a disaster like this terrible tragedy could happen again," said Bell.
CBS News Miami also learned more about the timing of the collapse.
The pool deck collapsed more than four minutes before the building, but that does not mean the collapse started there. Investigators repeatedly repeated that they had not ruled out the possibility that something in the towers had initiated the collapse.
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Click here to see the Cross-Project Panel Theme 3: Timeline and Evidence Collection.