Disclaimer: I do thoroughly believe that 9/11 was a terrorist attack, so please don't start arguing whether it was an attack or inside job, focus on the question.
Also: I was about to post this in History but I figured that physics would be more suitable.
So the question that I have always wanted an answer to but never found one is the following:
Why was the glass broken in the Lobby of the Twin Towers but not above the impact zone?
So I watched the documentary of the French Brothers who followed the Firefighters and when they respond to the Attack they make their way to the North Tower and when they enter, you can clearly see broken glass.
The link to the scene of the documentary, the shattered window can be seen starting at 0:55 seconds. https://m.youtube.com/watch?v=XvUIQZ7t7Ak
But there's also a recording of the 911 responders who talk to the people trapped above the impact zone (I can't find the video on YouTube right now, will link it as soon as I find it) where a woman shouts to "break the windows".
So how is it possible that the glass on the 100th Floor is intact when the plane hit the building at the 80th floor, but the glass in the Lobby all the way down at the ground is broken?