>>942073350
because some people in government planned around a real terrorist plot. they knew about them and let them in the country anyway to do what they were going to do. however, they also knew that a plane wasn't going to take down a building, much less a third building that wasnt even hit by a plane.
read about Larry A. Silverstein as for why the wanted the buildings destroyed.
this was more of an israeli plot than a us gov one, though of course some us officals were involved. as for why they used a real terrorist plot?
because its far easier to cover up when you can send people -not in the know- to investigate a real terrorist plot rather then something you completely fabricated.