Knowitball

My prior post featured simulations by Kostack Studio of the Twin Towers collapses. What made those especially fascinating to me was that they removed the smoke, debris, and surrounding visual clutter, making it easier to see the broader structural behavior that the real footage often obscures. By far the most common response in the comments was: “Now do Building 7.” Fair enough. So here is Building 7. Before getting into the simulation itself, a quick reminder of the basic context: WTC 7 was not struck by an airplane, but it was heavily damaged when debris from the collapse of the North Tower tore a large gash into its south face. That debris ignited fires on multiple floors. The building’s water supply and fire suppression capability were severely compromised, firefighters were eventually pulled back for safety reasons, and the fires were left to burn uncontrolled for nearly seven hours before the building finally collapsed at 5:20 p.m. What I find so impressive here is not just the final animation, but what went into producing it. According to the creator, this WTC 7 simulation was built using more than 28,000 structural elements and roughly 703,000 constraints, incorporating actual steel dimensions, steel thickness, plastic deformation, and connection-breaking behavior derived from physical parameters. In other words, this is not some cartoon sketch of a collapse. It is a serious attempt to model large-scale structural behavior as faithfully as possible with the information available. And I also appreciate the creator’s candor. He does not pretend this simulation is a perfect recreation of exactly what happened, down to every beam, every floor panel, and every fragment. Nobody can do that. A real collapse of this complexity becomes chaotic very quickly, and even with extensive modeling there are limits to what can be known with absolute precision. That honesty is part of what makes the project more compelling to me, not less. This is not being presented as an official NIST model, and it is not being offered as final proof of every detail. It is a visualization - an informed structural simulation built from the available evidence, the known geometry of the building, video observations, and the broader body of engineering work that has been done over the years by NIST and others. And that is exactly why I find it worth sharing. One of the biggest problems in discussing WTC 7 is that most people only know the exterior video. They see the outer shell descend and then leap immediately to conclusions. What they usually do not see is the internal failure sequence that, according to NIST and many subsequent analyses, was already underway before the visible exterior drop. This simulation helps make that concept easier to understand. It does not settle every argument. It does not reproduce every last detail with magical perfection. But it does provide a serious, visually clear attempt to show how the building could fail internally before the exterior facade gave way, and why the final visible descent can look simpler from the outside than the underlying structural reality actually was. So no, none of us should pretend this is “exactly” what happened in every microscopic detail. But as a close large-scale reproduction built from the best information available, I think it is genuinely fascinating. And given how many people demanded “Now do Building 7,” I hope this helps answer at least some of those questions.