This is pretty far-out stuff, but it is not impossible. The 1993 WTC bombing had all kinds of funky stuff going on where the FBI knew a bombing was going to happen but failed to stop it. So it would, at least, be hard to prove something along similar lines did not happen in OKC. Also there were reports of neo-Facist groups cheering the 9/11 attacks. I don't know if we will ever know what did happen, but it isn't looney to suspect McVeigh did not do it by himself. Bin Laden-trained terrorists had the embassy bombings under their belt, and they sure seem to know the weaknesses of buildings. Careful planning and expertise are much more likely to be successful than a lone wacko with a truckload of ANFO.
One thing I am pretty sure about is that 747s do not blow themselves up on their own.
Re#62 I never bought the exploding centerline tank theory either.If it was explained away so easily on this premise,why hasnt this happened before?Or afterwards?I honestly believe there is more to the 800 story.And I dont where a tin foil helmet!