Every thing, be it a tall skyscraper, a lofty mountain, or a mere mole hill, has a single destiny: To become flat, to fall, wear or settle down into flatness. This is the way of the world because the world warps the spacetime in which those things stand in a way that pulls the atoms they are made of towards the center of the planet. That this is true is evidenced by the fact that the largest region of the Earth that is made of molecules that are not well attached to each other is basically flat. (The oceans and seas.) Even the harder stuff such as rock and dirt is mostly flat around the earth. Be impressed with the jagged and broad Front Range of the majestic Rocky Mountains, but after you are done looking at them turn around and behold the essential flatness of the Plains and Midwest. Most of Asia is pretty flat as is most of Africa. The biggest thing going in South America is the Amazon Basin. Again, flat. Obviously, “flat” is a somewhat subjective term, but we can truly and scientifically divide the surface of the land of the Earth into regions of mountain building and regions of continuous, relentless, enflattening. The only reason that everything isn’t more flat is because, even though the destiny of all the atoms is to be part of one great flatness is real, there are also other effects.
If two continents run into each other, you get mountains. If a big bank provides the financing and a corporation has the will, you get a sky scraper. If a department of transportation gets the funding, and there is a river, there will be a bridge somewhere. These short term effects upon the earth create the bumps and high spots. Temporarily.
So yes, a bridge or a building falls down because of gravity, and now you are annoyed at me because I just spent 389 words stating the obvious. But wait, there’s more.
I state the obvious here not because you need to be reminded of this great truth (though we can all use that reminder now and then), but because the reality of gravity generates a bureaucratic situation that is the more proximal reason for the collapse of a condo.
Everything is broken. Some things are only barely broken, possibly invisibly broken, so maybe not technically broken by some mundane human standard, but at the molecular level, there is an atom here or there out of place (a flaw) or a vulnerability that is more of a broken design element than an actual break. Things like buildings and bridges, and a wide range of important machines, are regularly inspected to find these broken elements, in order that failure does not happen unexpectedly. But since everything is broke at some level, the bridge or building or machine is not discarded or rebuilt every time a problem is found. Rather, there is a threshold of how many breaks, or how bad the breaks are, beyond which we try to not let the brokenness pass.
But the ideal threshold is not known, merely estimated. And, there is a more conservative and a less conservative approach. Then there are errors and flaws in the system of looking for and keeping tracks of the breaks. There are corporate, institutional, and political pressures to not acknowledge that there is a problem. Sometimes that gets to the point of an enigmatic fedora wearing dog having a cup of coffee in a flaming restaurant.
And then the condo collapses, or the bridge falls down, and there is a … well, reassessment.
It happens in stages. First you build all the bridges such as the numerous bridges built across rivers and streams as part of the US Federal Interstate projects of the 1950s. Inspections happen, but the threshold is not sufficiently conservative, or the methods of inspection are not as good as they could be, or maybe there are pressures to ignore the data or move the threshold. Then the Schoharie Bridge collapses. From Wikipedia:
The Schoharie Creek Bridge was a New York State Thruway bridge over the Schoharie Creek near Fort Hunter and the Mohawk River in New York State. On April 5, 1987 it collapsed due to bridge scour at the foundations after a record rainfall. The collapse killed ten people. The replacement bridge was completed and fully open to traffic on May 21, 1988. The failure of the Schoharie Creek Bridge motivated improvement in bridge design and inspection procedures within New York and beyond.
That entry is a little misleading, suggesting that an unusual flood did something unusual to the bridge. Yes, it was a record flood, but records for that stream post date the building of a major reservoir upstream. The previous record was only from 1955, and most years the highest floods were nearly this high. In other words, no one was that surprised about the water level coming off the dam of the big reservoir, and no one was surprised about the big rainfall that happened downstream from the dam and upstream from the bridge. It was the fact that they happened over the same few days that rose the level to a record high, but not an outlandish record high. The bridge was built broken, in the sense that it was vulnerable to scouring. Today, interstate bridges are built with better foundations so this happens less, and they are inspected more.
But here’s the thing: As noted, this led to better design and inspection. But it also led to a lot of bridges being repaired all of the sudden.
I have not found a study that links major news-worthy failure to policy changes. But I can tell you that in the decade after 1987, there was a huge push to rebuild and update bridges to the degree that for a few years, I made a living on it, since most bridges in New York and New England pass by historic homes, old mills, or threaten Native American sites, as a function of how rivers, streams, roads, paths, hydrology, and settlement patterns work. I’m pretty sure similar things happened after the collapse of the I-35W bridge in Minneapolis a few years ago. And now, condos.
I think it works like this. At any moment in time there are identified problems with all the buildings or bridges of a certain class. By class I mean “Condos on barrier islands in Florida” or “Interstate bridges” and so on. The number of problems increases over time, but of course, many of those problems are dealt with as they are found, or at least, eventually. But the number of outstanding problems tends to increase because absent outside forces, the institutional, economic, and political forces that tend to lead to problems not being addressed tend to work a little at a time to enhance complacency, and sometimes, just plain corruption or stupidity.
While this is happening the public perception is essentially null. It isn’t on anyone’s radar screen. Even if you know about this or that problem, regular members of the public are not tuned in to a steadily ageing infrastructure that is associated with a steadily growing set of problems. Expensive problems. Annoying and time consuming problems. Problems that are easy to ignore, and really, not even know about to begin with. So, we are dogs with fedoras sipping coffee in a burning building. Everything is fine.
But then the condo collapses, or the bridge falls into the ravine. The public is astounded, shocked, made fearful, angry, and demands action, but generally, remains focused on that one event, that one structure, that one failure. Then, that is over and everyone forgets, and never really knew that there were a dozen condos or bridges at that level of broken, but only one failed because failures tend to come one at a time. The public is also mostly unaware (though certainly not everyone) of a response by the powers that be, the inspecting agencies and so on, that involves the sudden increase in inspection rate, the betterment of standards, and ultimately the application of jackhammers and pouring of concrete and leveling of footings and so on. The number of inspection issues suddenly drops to an acceptable level (but they are of course still there, again, unperceived by the public) and start to build again.
The improvements in engineering, materials, and inspection procedures hopefully lasts longer than public concern. The industry behind the infrastructure improves. But the social and political infrastructure seems to not improve much, or does so only temporarily. I put this pattern in a chart:
This is how a bridge or a condo falls down.