It's over-engineered unless a big truck bomb goes off next to it, or an airliner hits it, or it's subject to a significant earthquake--in which case it will then hopefully be just-right engineered.
The original WTC towers were already over-engineered. They could not be brought down by a plane hitting them, just like previously a plane hit the Empire State Building and it also did not collapse. That's why they needed the planes plus [redacted] in order to bring the towers down.
You've got the right mindset, but your conspiracy is backwards. The plane that hit the Empire State Building DID cause it to collapse, but the leaders of the media, academia, and construction industries formed a conspiracy to quickly rebuild it and pretend it never happened.
Edit: In case it's not obvious, they did this because they knew skyscrapers would be essential to the future growth of New York, and they did not want the public to be scared of them.
The joke is on us for accepting a story that could be verified by computer simulation, but for which a computer simulation was never written.
Also the report written on it only needed to prove that the fuel leaked from the tank. From that point on it was assumed on the report that the destruction we saw was caused simply from the fuel.
That is a hypothesis that is amenable to computer simulation. My sense of humor finds it funny no one has simulated what happened on a computer (well, those who tried have reached different conclusions, which is actually hilarious).
