Here is video of the Miami beachside condominium that collapsed at ~1 AM on 24 June 2021 (https://youtu.be/KR29pLccutY). There are many news stories about this now.
An engineering professor at Florida International University has used satellite data on ground elevation (a measurement technique used since at least the late 1970s) to write about the steady sinking of land in Miami, including the site of the condo, since 1990. There is a lot of beachside construction in Florida on landfill. This condo was actually built on sturdier ground (I’m guessing an ancient barrier island), but landfill is right next to it on the west side, where other similar buildings are located (and thus a bit further from the shoreline).
In 2018, a building inspector engineer issued a warning that there was serious damage to the building stemming from an inadequacy of foundation integrity. Nothing was done. In another report, I read that the development-friendly local and state authorities had freed the Miami real estate industry from “excessive” regulations by only requiring building inspections every 40 years! (I find this hard to believe, but it was a news report posted on the internet).
By now it is clear that the cause of the collapse was the softening of the ground under the building by the infiltration of seawater over the years since the building’s construction. Because such a large building is very heavy, especially in comparison to a simple beachside bungalow, the weight of the structure put tremendously higher downward pressure on the ground below its foundation, diminishing the integrity of the increasingly soaked soil, and thus speeding its ultimate loss of cohesion.
Now, some words about structural stability in a gravitational field. Earth’s gravity arises from its huge mass (compared to anything else humans are used to) and it points toward the Earth’s center, which means “down.”
Buildings, bridges and many other structures erected by humans on the surface of the Earth are designed to remain stable by having rigid vertical structural members (i.e., columns) to transmit the weight of the structure into the ideally “solid” ground below, which in turn distributes the pressure of the building’s weight (as mechanical stress) into the body of Planet Earth. The contact zone between the building and the Earth is usually a cross-braced foundation structure.
Those weight-bearing vertical supports are cross-braced by horizontal rigid structural members (i.e., beams, and in stronger designs by triangular frames: trusses). This way the entire building has the structural integrity of a “block”: the Earth holds it up, and its cross-bracing holds it together.
Essential to the building’s stability is the integrity of the earth below it: its solidity. When that solidity is lost, such as by water infiltration softening, and becomes nonuniform, then the building can begin to sink in a lopsided manner. Such tilting means that now gravitation forces no longer align perfectly with “vertical” columns (since they are tilted) but also has “lateral” components of force directed along the cross-bracing (which is also tilted).
Such new lateral forces transmitted by the cross members against the sides of the columns add a sideways momentum now pushing to tilt the building over, and are also forces working to tear the building apart from top to bottom.
At some point of building tilt, such unevenness of the distribution of gravitation stress throughout the structure, now no longer strictly vertical, puts more tensile or compressive stress (depending on the orientation of the member) than one or more of the structural members can sustain without buckling; or some of the bolted, riveted or welded joints between members can sustain to keep from ripping open.
Such structural failures remove pathways for the building’s gravitational stress to find its way to ground. So the structural members of the building’s frame that are still connected see an increase in the stress they must contain and transmit to Earth to hold up the building.
This takes those still intact members and joints more quickly toward their failure points, and the weakest among them give way. In this way an accelerating cascade of structural failures occurs, and the entire building can seem to suddenly “deflate” and collapse.
Such a collapse will be seen to propagate through the building as a wave of “deflation” from the regions of first failures to last failures, which, depending on the configuration of the undermining forces, can be left-to-right or vice-versa, and bottom-to-top or vice-versa.
The World Trade Center Towers building collapses of 11 September 2001 occurred from the top down: the dynamic force of collapsing mass above any given floor (the conversion of gravitational potential energy into mass acceleration) being beyond the yield strength of the vertical columns and cross-bracing joints at each floor-level, which were only designed — with a significant safety factor — to withstand the static stress imposed by gravity. The collapse of the smaller World Trade Center Building 7 proceeded from the left to the right because of a buckling of a column weakened by fire softening.
The Miami condominium collapse of 24 June 2021 progressed from bottom to top, first on the “left” side, and then on the now laterally unsupported “right” side (as seen in the video captured by a surveillance camera).
I would guess that what is happening now in Miami — and elsewhere — is a scramble to point fingers assigning blame and to evade responsibility; people seeking to sue somebody for losses of relatives, property and illusions; to get insurance payments, or to avoid paying them; to protect their money, investments, property and advantages of location; and to run away from their fears and hide from facing up to the realities of implacable Climate Change (in the form of sea level rise for Miami) plowing steadily into the American “good life.”
Climate Change is like an enormous steamroller that is inching slowly but implacably along the open road of our projected expectations, to roll over and flatten our comfortable situations.
Since we are all “cemented in place” in those personal comfort situations, that steamroller is bit by bit squashing us: first ‘here’ then ‘there’; some by sea level rise; some by hurricanes razing all; some by wildfire; some by deepening and eternal heat and drought; some by waves of disease pathogens sprung from out of formerly deep recesses in the wild; some by the increasing withdrawal of food availability; and some by the infighting all this sparks among us and that causes casualties from our war with ourselves.
First we lose our illusions, then we lose our money, and finally we lose our lives.
Those who refuse to face reality and relinquish their illusions will cause the most damage to their fellow human beings, by being rabidly competitive, as they slide down the cascade of suffering longer and ever obsessed to the death with their unrelieved anxieties of avoiding losses and pain. Those who jettison their illusions and face reality will a least gain the comfort of finding the company of similar people.
Even as the steamroller inches forward toward us, for everyone “the future is uncertain, and the end is always near.” One can pin oneself to an obsession with “the end,” and its avoidance; or one can open oneself to an appreciation for the processes of life, and to the sharing of such appreciation.
Climate Change is now our great teacher, and its lessons range from stark terror to transcendence. We have no choice but to live out those lessons, but we do have some choice in which of those coming experiences we can aim our personal selves to.
Photos from the news story (series) linked in two comments, below:
The beachfront looks like an ancient barrier island to me (my guess). The “flats” behind it look like landfill (“reclaimed land”). I suspect all this land is “wet” below a shallow depth from the surface. I also suspect that depth has been decreasing with the sea level rise over previous decades, and which continues.
27 June 2021, using Picture #1 for reference:
The surveillance camera that took the video of the collapse is located at the left-most, furthest ‘up’ seaward-side corner of the blue pool seen to the left in this photo, just below the large area of greenery. The camera was pointed diagonally across that pool, straight at the central portion of the building that collapsed. That central portion collapsed first, from the side closer to the surveillance camera and then dragging its backside (the side furthest from the surveillance camera) down. To me it seems that “the bottom dropped out” and not that the roof collapsed and pancaked down pulverizing the building. After that central section was all down, the squarish tower portion closest to the beach tottered, twisted ‘slightly’ clockwise as viewed in this picture, and then also collapsed by “the bottom dropping out.” You can see the higher pile of rubble left by that tower section collapse. I would guess that the section of ground (subsurface) between that outer tower section and the part of the building still standing, and aligned parallel to the shoreline, is the area of greatest weakness and loss of integrity. It is also possible (as others are commenting) that there had been a weakening of the reinforcing steel inside the concrete columns of the building because of the corrosive action of salty sea air and underground flooding since 1981 when the building was constructed. The conclusions of the forensic engineering reports, which will doubtless take many months to finally arrive at, will be interesting — if they are not distorted by CYA.