“Buildings in America don’t fall like this. ”
Photo: Chandan Khanna / AFP via Getty Images
Five days after a huge segment of the 12-story condominiums of the Champlain towers collapsed, the north wing of the building recalls the devastating loss of life, its tattered grid of interiors occupied moments before by sleeping residents. 150 of these residents are still missing and 11 people have died. Such a rare catastrophic event demands immediate responses: How can a 136-unit apartment building in an affluent neighborhood near Miami Beach, which is only about 40 years old, collapse? “Buildings in America don’t fall like this,” Surfside Mayor Charles Burkett said at a press conference Friday. “There is a reason. We have to find out what that reason is. But the factors – and there will likely be multiple factors – that caused the collapse of the South Champlain Towers may not be fully revealed for weeks.
The sheer incongruity of a suddenly collapsing building – especially a recent coastal building designed to handle extreme weather conditions, including hurricane-force winds – hints at an act of God explanation. And whether or not this particular disaster can be attributed specifically to climate change, our greatest existential threat, it should mark the beginning of a calculation as to why, as a country, we continue to invest so much in construction for reside in places that have been considered high risk, says Ann Tihansky, a physicist with the US Geological Survey. “This is the point of view of geologists, because we are always looking for the long term,” she says. “I think there is a topic of discussion here about infrastructure and smart investments for the future, using the best available science to make decisions and without putting ourselves at risk.”
Rising waters appear to be an extremely obvious scapegoat, especially in a state where leaders have largely attempted to ignore the climate crisis. As reports circulate that warnings from local building inspectors have gone unheeded, there are increasing requests for surveys in potential embezzlement. And, of course, there are conspiracy theorists looking at slow-motion security footage that they claim without proof shows signs of a detonation. What is more likely, suggests Guy Nordenson, a New York-based structural engineer, is not a single reason but rather several conditions that added to the structural failure. “There’s usually a whole bunch of things cascading down: you’ve got corrosion, you’ve got potential sag,” he says. “Inevitably there will be a number of causes that combine. The preliminary reports have led observers to various probable causes, and we’ll update this article as more evidence comes in.
According to a 2018 report, a consultant hired by the building’s board of directors discovered cracks, breaks and spalling in the structural concrete, a phenomenon known as chipping. In April 2021, a urgent letter from the chairman of the board of directors of the condominium warned that “concrete deterioration is accelerating” and noted that estimates for repairs had increased to $ 16 million, which is expected to begin this summer. Some most disturbing damage had been found in the underground parking lot, which last week had a water leak from the pool deck, where a resident of a fourth-floor apartment witnessed a hole opening just before the building collapsed. The chipping was so pronounced in parts of the building that it can be easily visible in recent Google Street View images, and while damage to balconies and exterior walls doesn’t necessarily threaten the integrity of the building, it could be a sign of real rot inside. If there was a column failure in the parking garage, it could explain how the building collapsed in what is called a gradual collapse.
Across the street, but located in adjacent Miami Beach, is Eighty-Seven Park, a new 18-story, 71-unit luxury tower designed by Renzo Piano and developed by Terra, which opened last year. During construction, residents of the Champlain towers complains of tremors and vibrations, with a condo board member writing to Surfside officials in January 2019 that workers were “digging too close to our property and we have concerns about the structure of our building.” The Surfside manager responded at the time that the city did not have jurisdiction to stop construction and advised the condominium board to hire an outside consultant to monitor any concerns. While construction work may compromise neighboring buildings – for example, a Murray Hill’s empty building collapsed last summer while workers were digging the adjacent construction site – that would be less likely to happen here, says Nordenson, where the new buildings are specially designed to withstand the vibrations created by the direct hit of a strong hurricane.
Surfside, like much of South Florida’s populated corridor, is located on a barrier island, a shifting sand berm that serves as a frontline coastal defense, absorbing the impact of storm surges and hurricanes. Millions of Americans also live on barrier islands, even though they are likely to be remodeled or even completely washed away overtime. Erosion may not have caused the collapse, but that’s one reason the building isn’t located there at all, says Albert Hine, a geological oceanographer who for many years taught at the ‘University of South Florida. “In 100 years, at high tide, most of Miami’s streets will be flooded, is that habitable? In the short term, there will be more hurricanes and more extreme weather events, ”he says. “Maybe we better not build any more skyscrapers here. The long-term goal is ultimately quitting.
According to a Report 2020, the ground beneath Surfside, like many areas of Florida, is sinking. Buildings can move, but the Champlain Towers were singled out in the report for their relatively higher sag rate, a rate of 2 millimeters per year. The tower was built on piles, explains Nordenson, which means that even if one of them was not properly anchored, the structure could be affected by settlement or incongruities in the ground, which could lead to additional geotechnical issues. The question this raises in Hine’s mind is whether the subsidence was a result of the potential use of backfill when the island’s building land was enlarged and whether the piles were actually anchored in the bedrock. “But if there was general sag, there would be concrete cracked and falling on every building along there, and I didn’t see that.”
One theory seemed extremely plausible to both Nordenson and Hine: a major structural flaw. the Miami Herald the editorial board drafted a scathing opinion piece noting that the Champlain Towers were built at a time when buildings were rising quickly, cheap and under-regulated, in part thanks to the national savings and loan scandal. “We know the building codes for single-family homes at that time were weak and their enforcement was lax, which became terrifyingly evident when Hurricane Andrew roared through southern Miami-Dade County,” it reads. in the opinion piece. “So when we look at the footage of destruction at Surfside, we’d be foolish not to wonder if the sloppy construction and the app to look the other way around from this era played a role. “
Florida’s geology – which relies on soluble limestone where cavities can form and eventually collapse – makes it the sinkhole capital of the United States. cars, roads and, in a few cases, entire buildings. But even smaller sinkholes can cause more minor structural problems over time. Miami-Dade County Mayor Daniella Levine Cava – who ordered all local buildings that are at least 40 years old be re-inspected within 30 days – said Monday there was no evidence that a chasm is responsible. That’s probably correct, says Hine – the specific location of the building is not a likely location for sinkholes.
If the spalling had compromised the structural columns, it is possible that the saltwater intrusion – which has increased in recent years due to sea level rise – has seeped into the columns, rusting and weakening steel rebars that reinforce concrete. It was something that the the former building manager had expressed his concern about 30 years ago, noting that he witnessed “a lot of salt water coming in from the bottom of the foundation … so much water, all the time, that the pumps could never keep up.” While coastal buildings are hypothetically designed to withstand exposure to the corrosive effects of salt water, conditions have changed enough in the 40 years since the building was constructed that it is worth considering. new theories about how structures might be compromised, says Nordenson. “Climate change puts a lot of stress on our buildings and infrastructure, from heat to flooding,” he says. “The initial information seems to point in the general direction towards questioning our assumptions about the sustainability of buildings. We need to think about how quickly things might go downhill under these particular circumstances. “