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

Tragedy in Taiwan: Collapse of the Golden Dragon Building

On Saturday, Feb. 6, a magnitude-6.4 earthquake shook the island nation of Taiwan.  Nearly all the high-rises in the southern city of Tainan withstood the quake without serious damage, partly because of new building codes enacted after a more severe earthquake in 1999 killed 2400 people.  But in the Feb. 6 quake, a 17-story building containing 96 apartments completely collapsed, trapping victims inside and causing the majority of the deaths involved.  As of Feb. 11, the confirmed death toll in the quake stood at 55, but many bodies probably remain in the ruins of the Golden Dragon apartment building, which was erected in 1994 before the new building codes took effect.  On Feb. 9, the building's developer and two associates were arrested and charged with professional negligence causing death.  Prosecutors claimed that shoddy construction was responsible for the building's collapse, saying that cans of polystyrene foam were used as fillers in the reinforced-concrete structure and that steel reinforcing bars were too short. 

Building a structure that can resist earthquakes is a challenge that modern structural engineers tackle routinely.  Very few steel-framed high-rises are seriously damaged by earthquakes, because the type of steel used in them has a certain amount of "give" which allows the stresses of a shaking foundation to bend but not break supporting members.  The only exception is the unusual case when an earthquake's period coincides with a building's resonant frequency and vibrations build up until something snaps.

Reinforced concrete is another matter entirely.  Concrete has excellent compressive strength, but it's brittle and doesn't bend easily.  If you try to bend it, parts of it are put into tension, and pure (unreinforced) concrete has almost no tensile strength, so it cracks when subjected to the pulling forces that bending causes. 

Many decades ago, construction engineers figured out how to embed "rebar"—steel reinforcing bars—in concrete to provide the tensile strength that concrete alone cannot provide.  Properly apportioned and applied, reinforcing bars can make concrete-framed structures just as strong as steel ones, with the advantage that setting up molds and pouring beams and floors can be a lot cheaper than assembling a steel frame.  So many buildings for which cost is an issue, such as apartment complexes, are made of reinforced concrete.

However, making such a structure earthquake-resistant is a challenge, especially if it was not originally designed that way.  A personal anecdote will illustrate this.  I attended the California Institute of Technology in Pasadena from 1972 to 1976.  That institution began its existence in 1891 as a vocational school funded by businessman Amos Throop.  By 1912, the main building on campus was Throop Hall, a reinforced-concrete-and-brick structure that stood until a 1971 magnitude-6.6 quake seriously damaged it.  Engineering studies showed that the structure was fatally flawed with regard to earthquake resistance, and would probably collapse in another quake of the same or greater magnitude.  So despite its historic associations, it was condemned and fell to the wrecking ball during my freshman year there. 

The problem of what to do with existing structures when building codes change is difficult, and municipal authorities rarely condemn buildings that are not obvious ongoing hazards simply because of a building-code change.  The Golden Dragon apartment building may have been erected in compliance with the codes as they stood in 1994, but emotions are running high after the disastrous collapse, and the developers will have to argue in court as to whether they behaved responsibly during the construction of their building.

One way to enable reinforced-concrete structures to withstand earthquakes is to make ductile joints between the horizontal and vertical members of the structure.  This will allow the building to "follow" horizontal ground movement without imposing fatal strains on the supporting walls.  The fact that lightweight material such as plastic foam was used as fill may not necessarily indicate shoddy construction.  And the length of rebars is something that may or may not have had anything to do with the building's collapse.

The good news coming out of this tragedy is that more buildings didn't collapse, as for example happened in Haiti in 2010.  What few building codes existed there were not enforced, and although there were few structures more than three or four stories high, over 200,000 of them collapsed and the death toll exceeded 100,000.  As a rapidly developing nation, government officials in Taiwan did the responsible thing following the 1999 earthquake and imposed building codes that required buildings to withstand a certain level of earthquake shocks.  The fact that only one major high-rise collapsed, and that one a pre-1999 structure, says that the new building codes have been largely effective.

In addition to investigating the construction of the ill-fated Golden Dragon, Taiwan officials may want to consider a program of inspections of pre-1999 structures with an eye toward preventing more such tragedies in the event of a larger earthquake.  Even if the conclusion is that things are okay, this would be a reassuring thing to find out.  And if some other structures are like time bombs waiting to be set off by a large earthquake, the time to find that out is now, not when the next big one hits. 

Sources:  I referred to news items from Agence France-Press carried by the Australian Broadcasting Company at http://www.abc.net.au/news/2016-02-11/taiwan-court-hears-of-critical-flaws-in-quake-hit-high-rise/7160954 and UK's Daily Mail at http://www.dailymail.co.uk/wires/afp/article-3439998/Taiwan-developer-grilled-collapse-quake-building.html.  I also referred to the Wikipedia articles on earthquake engineering and the California Institute of Technology.