elphabaizkool well your dad did his homework there were not one bomb or 2 but many... and that is told by more people you would thinkand if you watch some vids of the collapse you will notice there are some tiny smoke clouds every 30 - 40 floors. they just pop up before the top reaches them.and that on both buildings i wonder there whose belong to :P you should takeyour time to watch something like loose change i know its hard to believe it well you don´t have to but at least think about it