Here's a little fact: NIST never provided calculations or a model for how the towers came down sequentially. They only gave a reasoning to the start of the collapse and made an assumption for the rest of the timescale. They completely skipped over how the core columns gave way throughout the collapse. Is this event not significant enough to study for the sake of future building design? Luckily there are engineers who attempt to explain the collapse sequentially, and guess what? The conclusion is that it's simply not possible, and defies the laws of physics if it truly was solely a gravity driven collapse.
