Being an American, and residing in America at the time that this happened, I can say that this was something that was already brought up shortly after the tragedy. It was the first thing on all of our minds - wtf are the airplane parts? Almost every single detail about Sept 11th has not been explain very well by the government, and unfrotunately most everyone else's govmn't has a hand in helping to cover it up...
Sometimes it is hard to see any point to finding answers. I say just do away with all the retards in power still and stick new ones in there... haha and just start the whole things over. Should be good for a few hundred years at least...