The JetSet Roof Collapse: Causes Yet Unknown

 

Many prominent people were in the exclusive but crowded venue of the JetSet nightclub on Avenue Independencia in the Dominican Republic's capital city of Santo Domingo late Monday night, April 7.  These included a provincial governor named Nelsy Cruz, ex-Major-League baseball players Octavio Dotel and Tony Blanco, and famed merengue musician Rubby Pérez, whose singing was the main attraction.  An estimated five hundred people were jammed into the building, which occupied a corner block behind some trees and a canopied entryway.

 

Around a quarter to one A. M., someone pointed to the ceiling, saying that they had seen something fall.  Seconds later, a video showed Pérez himself on the stage as he glanced at the ceiling.  Thirty seconds after the first warning sign, the roof over the entire main room of the club collapsed, crushing people under the weight of concrete slabs. 

 

By Friday, the death toll stood at 225, with almost as many injuries.  Pérez, Dotel, Cruz, and Blanco were killed, along with 17 U. S. citizens and numerous residents of other countries.

 

Any time a crowded building collapses with loss of life, especially in the absence of natural causes such as hurricanes or tornadoes, questions are sure to arise about the cause.  While evidence to support a conclusion in which we can put confidence is lacking at this time, the little we know about the circumstances so far can guide cautious speculation.

 

According to news reports, the building was erected in the mid-1970s as a movie theater.  Theaters, coliseums, and other locations for public performances require long unobstructed sight lines, which means that the roof has to be supported only at the edges, with trusses spanning the distance from wall to wall.  Firefighters saw large blocks of concrete among the fallen rubble, and at least one remarked that he saw no "rebar" (reinforcing steel bars) in them. 

 

In the U. S., most spaces at least fifty feet (15 meters) wide or more will have primarily steel trusses supporting the roof, which may have a thin layer of concrete above them for waterproofing.  But the main supporting strength is in the steel trusses. 

 

It's possible to span such distances with a roof made primarily of concrete, but there has to be reinforcing means such as rebar or pre-tensioning cables and thicker concrete beams to support the rest of the roof.  The state of the construction industry in the Dominican Republic in 1975 is unknown to me, but it's possible that the builders of the original structure made the roof just strong enough to support itself.

 

If, as the fireman who saw the concrete slabs speculated, extra weight was added to the roof over the years, such as air-conditioning units or even solar panels, the weight might exceed the carrying capacity of the roof. 

 

Concrete is not like steel, which is homogeneous enough to fail almost as soon as it's overloaded.  Depending on how the concrete was mixed, a piece of concrete that is fundamentally overstressed may hang together for a relatively long time as cracks slowly propagate and stresses reorder themselves to go through the remaining connected pieces of the mix.  Concrete is more likely to fail with a crumble than a bang, although when the most stressed part fails, it usually takes the rest with it pretty fast.

 

This catastrophe recalls the collapse of the Surfside Condominium in a Miami suburb in June of 2021.  Repeated inspections of that structure pointed out serious deterioration in some supporting columns, exacerbated by recent building modifications.  Renovations had been scheduled before the collapse, but the building fell down, taking 98 people to their deaths with it, before they could be done.

 

It is not known at this point (at least by me) whether Santo Domingo required regular building inspections of places where people gather in large crowds.  Even if such inspections were required, it is not easy to inspect a concrete slab underneath layers of roofing material, although there are ways of doing so.  And even if inspections were required, they might not have been done on schedule.  And if they had been done, adverse findings might have been ignored.  The owners of the nightclub are reportedly one of the wealthiest families in the Dominican Republic, so they presumably could have afforded repairs if they were needed.  Now they're going to find out if they can afford the legal nightmares of liability for the two-hundred-plus deaths the collapse of the building caused.

 

If anything good can come out of this tragedy, it may take the form of improvements in building codes and inspections.  Every industrialized nation has followed a long road from basically free-for-all construction methods to increasingly strict regulation of building codes, materials used in construction, design methods, and inspections before, during, and after a building is erected.  While there is an argument to be made that we have now passed the point of diminishing returns in parts of the U. S. and building codes now serve to restrict the housing market more than improve safety, there is a lot more room on the other end of the road where inadequate codes and inspections allow conditions to happen such as the circumstances that led to the JetSet tragedy last week. 

 

Perhaps this horrible accident will stimulate a conversation in the Dominican Republic about building codes, inspections, and where on the tradeoff curves the country wants to reside.  There is always the possibility that some extremely rare and unlikely cause will be found—sabotage, perhaps, or a freakish set of circumstances that can't be predicted.  But currently, the little we know indicates that carelessness and perhaps incremental loading of the roof without an engineer's inspection and approval may be the cause.  If that's the case, then there is something the citizens of the Dominican Republic can do about it:  demand safer buildings, and whatever regulation and enforcement is required to get them.

 

Sources:  I referred to a CNN article at https://www.cnn.com/2025/04/10/americas/what-happened-dominican-republic-collapse-latam-intl/index.html and the Wikipedia article "JetSet nightclub roof collapse." 

 

P. S.  A month or so ago, editor Michael Cook of the website mercatornet.com notified me that his website would soon cease operations.  For over a dozen years, Michael did me the compliment of reprinting many of my blogs, always with my permission, and often with the result that they reached a much wider readership than they otherwise would have.  Originally one of the few conservative family-values-oriented news outlets in Australia, Michael's site recently experienced increased pressure from competition from similar sites and a lack of readership numbers that finally made it uneconomical to continue.  I wish Michael the best in his future endeavors and remind him that all the good things his website did have still been done, and will have unimaginable effects in the future—mostly good ones, I expect.---KDS

The Davenport Apartment Collapse

 

Around 5 PM on Sunday evening, May 28, if you had been standing near the corner of West 4th and Main Streets in downtown Davenport, Iowa, you would have seen The Davenport apartment building yield up about a third of its facade to gravity.  With a loud rumble and a cloud of dust, more than a dozen apartments in the building collapsed, taking three lives and trapping Quanishia Berry in her fourth-story apartment for over twenty-four hours before she was rescued.  Like many engineering disasters, this one was the outcome of a series of actions, or inactions, that could have prevented it.  But now that it's too late for the victims, we can at least learn something from the sequence of events that preceded the tragedy.

 

The Davenport was built in 1907 and at six stories, was probably one of the most prominent structures in the city at that time.  The residents living in it just before the collapse complained of odd creaking noises, cracks in the floor underneath carpets, and window frames pulling away from walls. 

 

The Davenport's owner, Andrew Wold, paid a structural engineer in February to conduct an inspection of the building.  The engineer's report stated that although bricks in the facade were cracked, the flaws were not an "imminent threat to the building or its residents."  In later reports, the last one dated four days before the collapse, the same engineer said that now, several patches of bricks "appear ready to fall imminently, which may create a safety hazard to cars or passersby."  Evidently, a portion of a load-bearing wall behind the brick facade had collapsed, transferring loads onto the facade itself, which was not intended to carry such loads.  This would explain the bulging and other issues noted by the residents.

 

Some residents became so alarmed by the deterioration that they broke their lease and moved out before the collapse.  But others took the word of the landlord that there was no immediate danger. 

 

It is always a judgment call to determine when a building's condition is so bad that it must be evacuated.  Wold had obtained estimates for shoring and supporting parts of the building, but at $50,000 he regarded them as too costly.  The owner of the masonry repair service who provided the quote said that he wouldn't allow his workers on the site without such repairs.  So here was a technically competent person saying he wouldn't even let his employees near a place where residents were living twenty-four hours a day. 

 

How could things have gone differently?  There is evidence that Trishna Pradhan, the city's chief building official, thinks she might have been able to prevent the tragedy by issuing an evacuation order, something she was presumably authorized to do.  The evidence is that a few days after the collapse, she resigned her position.  Another official gave the reason for her resignation as having "wrongly categorized an inspection of the building."  While orders to evacuate a structure immediately are serious things and involve potential legal liability, failing to issue such an order can have worse consequences, as it did in this case. 

 

A building is an extremely complicated structure, and predicting down to the minute when something as large as The Davenport will collapse is essentially impossible.  But when large cracks appear in significant places and the facade begins to bulge visibly, even the average non-technical person would agree that something bad may be about to happen. 

 

One article on the collapse interviewed engineers who cite modern technologies such as vibration sensors that can detect abnormal shifts and movements that occur before serious structural failures.  These can be installed in suspect structures and monitored, but then the question becomes, "How much movement is too much?"  These methods are still experimental, and the expense of installing and monitoring them is one more reason to simply leave things as they are.

 

And that was the main sin of omission committed here.  No one wanted to be the person who stuck his or her neck out and said, "Okay, this place is about to fall down, and we need to get the residents out before it does."  Only a few occupants made this decision on their own, which is not to blame the ones who stayed.  After all, they were told that there was no imminent danger, and up to 5 PM on May 28, that statement was correct, depending on how you define "imminent." 

 

That word did come up in the engineering report four days before the collapse, and should have motivated someone—the landlord, the city—to act.  But yet another decision point was passed, and events moved on to their tragic conclusion.

 

Whoever takes over from Trishna Pradhan as chief building official is going to be a lot more careful about classifying the results of building inspections in the future, one would hope.  And as the technology for sensing vibration in buildings gets cheaper and more available, it might be a good thing if buildings with structural problems were required to have such sensors installed.  The most valuable thing about that would be that we could get lots of data from normal wear and tear, and could get a better idea about what happens with regard to vibrations as a building gets closer to falling down.  Electronic infrastructure sensors like these are available for new buildings, but it would be a challenge to install them in old structures, although not impossible.

 

I can't close this blog without remarking on the likely class of residents who occupied The Davenport in its final days, and whether their complaints might have received more attention if they had been, frankly, richer.  But rich people don't live in 116-year-old run-down buildings in the middle of deteriorated city centers.  Just this morning I was reading in the Old Testament book of Proverbs, and came across one that seems to sum up what happened here:  "The poor man utters supplications, but the rich man answers roughly."  Next time, the rich man needs to listen more carefully, and take more thought for the safety of his fellow human beings.

 

Sources:  I referred to the AP article "Many warnings before collapse" at https://apnews.com/article/iowa-davenport-building-collapse-621844c0d6c206ced4639ddcf443eb80 and the Wikipedia article "Davenport apartment collapse."  The Proverbs verse is Prov. 18:23 from the New American Standard Bible.

Digidog To the Rescue: The NYC Parking Garage Collapse

 

On Tuesday, April 18, there were, by one estimate, about 40 cars parked in a four-story parking garage in the financial district of Manhattan.  When the structure was built in 1925, it may have been one of the first purpose-built multi-story parking garages in the world, as the value of a parking place in the middle of the Roaring Twenties was probably higher near Wall Street than anywhere else and would have paid back the owners in a short amount of time.  Over the years, city inspectors cited the garage for various violations, including spalling concrete and other signs of structural deterioration.  None of these was apparently serious enough to cause the city to condemn the building or close it until repairs were completed.

 

Around 4 PM last Tuesday, the building suddenly collapsed.  One report says the roof level caved in and set off a chain reaction that caused the entire structure to pancake.  Seven employees were injured and the building's longtime manager, Willis Moore, was killed.

 

A week earlier, the city had held a news conference about its use of a new robot called the Digidog in both crime-fighting and other emergency situations.  One of the fire department's Digidogs, a four-legged device painted with Dalmatian black spots on white, was sent into the collapsed building to search for survivors, and video-equipped drones probed the wreckage as well.   In the event, all the survivors were rescued, some from precarious perches amid the rubble, and no firefighters were injured in trying to save them.  This was the first time that the firemen's Digidog was used in a building collapse, but it won't be the last.

 

Buildings have been falling down ever since there were buildings.  Before the modern era, the only way to learn engineering was by experience.  Trial and error is a hard teacher, especially when the errors are several stories high and collapse while people are using them.  But the knowledge of just what was needed to keep a wall or a tower from caving in was jealously guarded by those who needed to know, and led eventually to such amazing creations as the medieval cathedrals of Europe.

 

Once the properties of materials became quantifiably known and their application through mathematical principles to structural engineering became routine in architecture, it was now possible to prove mathematically that a certain structure wouldn't fall down.  But that depended on the exact following of engineering plans, which were carried out by contractors and construction workers, and sometimes they made mistakes, as the engineers did too from time to time.

 

We won't know exactly what went wrong with the parking garage in Manhattan until forensic engineers comb through the wreckage and try to piece together the sequence of events.  The fact that the building was cited for dozens of code violations, including some that involved cracks, exposed steel beams, and other signs of structural deterioration, suggests that a deteriorated member—either poured concrete or steel or a combination—finally gave way under loads that it was probably not designed to have.  Photos of  what may have been the roof level after the collapse show cars densely lined up on it, and cars in 2023 weigh three to four thousand pounds, a lot more than the 2200 pounds of a Ford Model A, typical of what was parked there in 1925. 

 

The hope expressed in the early days of modern engineering was that, now that we have put the enterprise on a sound scientific footing, there is no excuse for anything to fail ever again.  In reality, failure is just as much a part of engineering as success.  The game is to control failure so that it either doesn't happen during the lifetime of the engineered artifact, or if it does, the failure's consequences are minor enough to effect repairs without serious harm to anyone or anything. 

 

With buildings, failures can range from minor issues such as window blinds that don't work, all the way up to the whole structure collapsing.  Obviously, more energy should be expended on preventing major structural failures, and in a regulation-intensive environment like Manhattan, few major signs of structural problems can escape notice.  But what to do about them once they're noticed is another question.  To condemn a building based on structural problems is a major step, and unless there is solid evidence that is rarely available, even New York City regulators hesitate to go that far.

 

While drones and robotic dogs are all very well, they are only useful once the tragedy has happened.  Technology is now being developed at my own school (Texas State University) and around the country to make buildings more self-diagnosing:  concrete that can tell you how healthy it is and whether it's developing internal flaws that would otherwise require impossibly costly means such as X-rays to determine.  The hope here is that long before a building gets to the point where it might fall down, the internal diagnostic tools will alert inspectors to exactly what is wrong and how dangerous it is.  At that point, the decision to repair, evacuate, or condemn can be made not on guesswork, but on quantifiable data that is presently not available.

 

Unfortunately, these types of innovations can practically be applied only to new construction.  Nearly everything that is built already can't benefit from them, and it is in the nature of buildings to be used until something better replaces them, or until they fall down.  So we will have to wait for decades until we have a built infrastructure that tells us enough about itself to allow us to make a good judgment as to whether collapse is imminent, or whether repairs can be put off for another day.

 

Until that happy time, we will still be hearing about building collapses from time to time.  Drones and robotic dogs may become as routine as fire ladders, but in the long run, let's hope we can avert every building collapse before it happens.

 

Sources:  I referred to articles carried by CBS News at https://www.cbsnews.com/newyork/news/lower-manhattan-parking-garage-collapse/, https://www.cbsnews.com/newyork/news/mayor-adams-robotic-dog-drone-used-to-assess-lower-manhattan-parking-garage-collapse/, and https://www.cbsnews.com/newyork/news/nypd-eric-adams-robot-dogs/, as well as the Wikipedia article "2023 New York City parking garage collapse."