Gosh, Peace, with your knowledge of 19th century choo-choos you've convinced me!
But forgive me; I'm just a humble builder who has to deal with loadings and stressings on structures to comply with Building Regs on a day to day basis, while in a previous existence I was quite familiar with the effects of various kinds of demolition charge on structures.
That ignorance aside, however,I have seen absolutely nothing from to dissuade me that what happened to the World Trade Centre buildings was not a direct result of the impact of two aircraft.
Furthermore, if any organisation really did possess the capacity to perpetrate such an act and shift the blame so effectively, I don't think it exists in the USA at present.
Sadly, the truth is always far more boring than fiction. Not that this will dissuade any of you from continuing to insist that the act was somehow more sinister. Such is the nature of conspiracy theories - there's a warm fuzzy glow from being a 'believer'.