By Architect Yermys Peña, CEO of Construger
Special for El Inmobiliario
When a structure collapses, the roar doesn't end with the fall. What follows is even more deafening:
What went wrong? Who allowed it? Could it have been prevented? Broken families. Lost lives. Wounded cities.
And amidst the dust, the mourning, and the bewilderment, the answers cannot be rushed. Headlines aren't enough. Indignation isn't sufficient. What follows is the most difficult and most crucial moment:
to understand with technical clarity what happened… so that it never happens again.
That is what structural forensic engineering does: reconstruct the collapse from the technical truth, when there is no longer room for errors or excuses.
9/11 and Surfside: When the world learned to listen to the rubble
The world has already experienced this. The collapse of the Twin Towers in 2001 was not simply the impact of a plane. NIST, led by Dr. Shyam Sunder, spent three years analyzing more than 10,000 documents, 236 pieces of steel, and hundreds of digital simulations. The debris was stored as evidence, and the conclusion changed history: it was a progressive collapse, triggered by extreme heat and the loss of fireproofing insulation. Since then, more than 30 international standards have changed.
In 2021, the Champlain Towers South building in Surfside, Florida, collapsed in the early morning hours, claiming 98 lives. Technical warnings had been in place since 2018. The NIST team, led by Dr. Judith Mitrani-Reiser, is still investigating, but evidence points to a garage slab weakened by leaks and accumulated corrosion. The debris was sorted and stored. The remains were scanned with laser technology, and the entire collapse was reconstructed using advanced structural simulations.
A modern structural forensic investigation is inconceivable without digital analysis models. Through specialized software such as ETABS, ANSYS, SAP2000, or Abaqus, engineers can recreate actual loads, buckling moments, crack propagation trajectories, or progressive collapse sequences.
These models allow for the identification of inconsistencies between what was designed and what was built, the validation of hypotheses, and the demonstration with data of why a structural element failed.
In both cases—9/11 and Surfside—simulations played a central role in identifying how, where, and in what order the connections, slabs, and columns collapsed.
As Dr. Sunder put it, “A collapse doesn’t happen all at once. It happens in stages. And with simulation, we can work backward through them to find the initial cause.”
A well-conducted structural forensic investigation should include:
- Site preservation before moving debris
- Photographic record and 3D scan of the collapse
- Extraction of concrete and steel cores for laboratory use
- Plan review vs. actual execution
- Digital simulations of structural behavior
- Evaluation of maintenance, modifications and actual use
- Drafting a technical report with findings and recommendations
Who should conduct the investigation? Certified structural engineers, court-appointed experts, municipal authorities, firefighters, the Public Prosecutor's Office, and independent experts. In cases involving victims, multiple simultaneous investigations are justified, provided there is traceability, coordination, and technical rigor.
And yes, these studies cost money. In the US, they can exceed $5 million. In Latin America, they range from $100,000 to $500,000, depending on the scope.
But the real question is:
what is the cost of not doing it? What is the cost of repeating a tragedy?
A city's structural memory isn't just in its plans. It's in its ability to listen to what its buildings are already saying. And in its technical will to act before they collapse again.
