A three-story building collapsed in Brooklyn, New York on Wednesday, November 11. As of November 12, at least eight people have died and 17 were injured. Our thoughts are with the families, the residents who lost their homes, and the crews working the site.
No cause has been determined, and this article does not offer one. It explains how a collapse investigation reaches an answer, and what the event is a reminder of for anyone responsible for a building.
What is known
The building held a ground-floor store with apartments above. City officials have said it fell into a construction site on the adjoining lot, and the New York City Department of Buildings is investigating. Officials have not said what caused the collapse.
How investigators determine what happened
A collapse investigation works from evidence, in a rough order:
- Secure the site. Stabilize what remains and protect the evidence.
- Document the debris. The way a structure comes to rest is evidence, so it is recorded before anything is moved.
- Gather the records. Drawings, permits, inspection reports, and repair history for the building and for any work nearby.
- Interview and collect. Residents, workers, and witnesses, along with photographs and video from before and during the event.
- Test and analyze. Materials and soil are tested where needed, and each possible explanation is checked against the physical evidence.
Findings come last. Early theories are often revised as the evidence comes in, which is why the responsible position for anyone outside the investigation is to wait.
What every building depends on
Every building relies on the same basics. A foundation carries the weight into the ground. A structural frame of columns, beams, and bearing walls holds the building up. Floors and a roof span between supports and tie the structure together. An envelope keeps water out. And every load, from gravity or wind, needs a complete path through the structure to the foundation.
When one of those is compromised, by age, water, alteration, or a change in the conditions around the building, the others are asked to do work they were not designed for. That is true of a three-story building in Brooklyn and of a condominium on the Florida coast.
What owners and boards can do now
None of this depends on the Brooklyn findings.
- Keep the records. Drawings, repair history, and inspection reports are the first things anyone asks for, and they are far easier to find before they are needed.
- Stay current on inspections. Milestone inspections and structural integrity reserve studies exist to check these fundamentals on a schedule.
- Report changes promptly. New cracks, movement, water intrusion, or construction activity next to the building deserve a call to a qualified professional.
We will update this article when investigators release their findings.
Have Questions About Your Building?
Our team has evaluated concrete and coastal structures across Florida since 1995. If your board or property has questions about cracking, corrosion, or the condition of a concrete building, we can help you assess it and plan ahead.
Schedule a ConsultationThis article is general information. It is not an engineering assessment of any specific building, and it is not a statement about the cause of any collapse.