What caused the Surfside condominium building to collapse?
Part 1 of 2: A series of events culminated up to the June 24th tragedy.
On June 24th, a large condominium building collapsed in the middle of the night in Surfside, Florida, a town several miles north of Miami.
About 55 of the building’s 136 units collapsed within seconds. As of July 6, 32 people have been confirmed dead, and another 113 remain missing, according to NPR.
The 12-story Champlain Towers South building was built in the early 1980s. Because of climate conditions in the area, buildings older than 40 years are required to undergo a recertification process to identify any structural or electrical issues. Exposure to salt air is corrosive to concrete and is a known problem, and hurricane winds and saltwater flooding add additional stress.
What we know
In 2018, an engineer was hired to undergo the recertification process of the building. As a result, the engineering consultant, Morabito Consultants, had reported major structural damage to the slab below the pool deck and “abundant” cracking and spalling of the concrete columns, beams, and walls in the garage under the tower. Spalling refers to the deterioration of concrete, sometimes causing flaking and the exposure of reinforcing steel bars known as rebar. The report recommended that repairs be made in order to maintain the structural integrity of the building. The report and estimate of the cost of repairs were given to the condominium board at that time. A new roof was being put on the building at the time of its collapse.
The town of Surfside received the required inspection report and numerous other documents within 16 hours of the building’s failure. A letter to the condominium association’s treasurer from Morabito Consultants on October 8, 2018, included pages of recommended repairs. One warned of failed waterproofing causing “major structural damage” on a concrete slab over a garage and said, “failure to replace the waterproofing in the near future will cause the extent of the concrete damage to expand exponentially.”
The letter further stated that the problem was that the waterproofing was laid on a flat concrete slab, not sloped in a way that would allow water to run off, an issue Morabito called a “major error” in the original design. The parking garage was partly underneath the pool deck, and that area showed signs of distress and fatigue. Photos were included that showed cracks in the parking garage columns, concrete crumbling, and exposed steel reinforcements on the garage deck.
Included in additional documents submitted to the town was an email that indicated the condominium association’s then vice president sent the report that included information about the slab and damaged concrete to a town building official as early as November 13, 2018. The documents also indicated that repairs were estimated to reach $9 million. A June 28, 2021, CNN media report on the subject confirms the town’s receipt of the report and a subsequent meeting of the association board on November 15, 2018, that the then-current town’s building official attended. The meeting minutes, as reported by CNN, state that the building official reviewed the engineer report, and while he noted that the report was not in the format for the 40-year certification, he determined the necessary data was collected, and it appeared that the building was in very good shape.
It does appear from the information in the documents that there were plans that included slab reinforcement and concrete and masonry repairs, among other repairs; however, they were not solidified until April of this year. According to the association’s attorney, the association took out a $12 million line of credit to pay for the repairs and went through a step-by-step process to get them done. Also, the pandemic slowed progress on getting the repairs underway.
Despite the suggestion of design flaws and failed waterproofing, it remains unconfirmed what caused the cracking. John Wallace, a professor of structural engineering at the University of California, Los Angeles, has participated in multiple forensic analyses of building failures and was reported in USA Today as saying that it could be slow degradation over time, maybe the concrete wasn’t placed properly, it could be that the ground had moved somewhat causing it — it could be multiple things. He said that the cracking concrete warrants investigation but cautioned there is nothing to indicate it was the cause of the collapse.
Researchers analyzing space-based radar had also identified land that was sinking at the property in the 1990s. The 2020 study found subsidence in other areas of the region, but on the east side of the barrier island where Surfside is, the condo complex was the only place where the issue was detected.
Experts said that the process of assessing what ultimately caused the building’s structure to fail could take months, involving a review of individual building components that may now be buried in debris, the testing of concrete to assess its integrity, and an examination of the earth below to see if a sinkhole or other subsidence was responsible for the collapse.
Also unknown is whether the original contractor built the tower to then-current design plans that likely would have required pilings to support the building to be anchored properly to bedrock.
Residents say that the garage was known for leaking, and there was frequently standing water in the garage. A former maintenance worker said that saltwater would seep through the building’s foundation during particularly high tides and that employees would regularly use two large pumps to pump out a foot or more of water from the garage.
Editor’s Note: Read part two of this article series to discover what insurance coverages and issues may be involved with this tragedy.
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