I remember seeing a documentary showing footage taken from inside one of the foyers, before the 1st tower went down. There was no need to see the jumpers, the impact when hearing them hitting the ground, the foyer roof or any surrounding cars was more powerful than the published visuals.
Although it wasn't planned - by the US government that is - 9/11 was the best thing that happened for G.Dubbuya who was under fire as a result of domestic policies & budgetary mismanagement. The approval ratings at the time pointed to him being ousted at the next election. 9/11 and the ensuing "war on terror" brought him an extra term in office at least.
Getting back to the "it wasn't planned by the US government" statement. I'm not into the conspiracy theory take but they're not entirely blameless. A number of years ago the CIA was offered intel, by a Nth African country where he was living in exile at the time, on a silver platter - the CIA knocked the offer back. The CIA/US government's policy, regarding intel & the cooperative passing over of information, was that it wouldn't deal with states with fractured or volatile/tenious relationship with them ie. most Muslim states.
I also read an newspaper article - detailed by a former Bush adviser - where the growing & imminent threat posed by Bin Laden/Al Queda was raised at an internal meeting. George Dubbaya said with words to the effect of "i'm not interested in Osama Who...... Hussain is the one i'm after."
I guess the Bush's business interests with the Bin Laden family allowed Osama to fly under the radar.