Here is overview that gives you just a couple of reasons to question the official claims the government makes regarding 9/11. This was taken from the Scholars for 9/11 Truth website. ST911 is a large organization consisting of scholars of all fields including physicists, engineers, architects, university professors, etc. In other words, intelligent individuals knowledgable in their fields who cant be easily blown off and discredited.
1) The impact of the planes cannot have caused enough damage to bring the buildings down, since the buildings were designed to withstand them (as Frank DeMartini, the project manager, has observed), the planes that hit were very similar to those they were designed to withstand, and they continued to stand after those impacts with negligible effects.
2) The melting point of steel at 2,800*F is about 1,000*F higher than the maximum burning temperature of jet-fuel-based fires, which do not exceed 1,800*F under optimal conditions, so the fires cannot have caused the steel to melt, which means that melting steel did not bring the buildings down.
3) UL certified the steel in the buildings up to 2,000*F for at least six hours before it would even significantly weaken, where these fires burned too low and too briefly--about one hour in the South Tower and one and a half in the North--to have even caused the steel to weaken, much less melt.
4) If the steel had melted or weakened, the affected floors would have displayed completely different behavior, with some asymmetrical sagging and tilting, which would have been gradual and slow, not the complete, abrupt, and total demolition that was observed.
5) There was not enough kinetic energy for the collapse of one floor to bring about the collapse of the next lower floor, even if the impact of the planes and the ensuing fires had been enough to cause the steel to weaken, which means that, even if one floor had collapsed due to the impacts and the fires, that could not have caused lower floors to fall.
6) There was not enough kinetic energy for the collapse of one floor to bring about the pulverization of the next floor, even if the impact of the planes and the ensuing fires had been enough to cause the steel to weaken and one floor to collapse upon another, which required a massive source of energy beyond any that the government has considered.
7) Heavy steel construction buildings like the Twin Towers, built with more than 100,000 tons of steel, are not even capable of "pancake collapse", which can only occur with concrete structures of "lift slab" construction and could not occur in "redundant" welded-steel buildings, such as the towers, unless every supporting column were removed at the same time, as Charles Pagelow has pointed out to me.
8) The destruction of the South Tower in 10 seconds and of the North in 11 is even faster than free fall with only air resistance, which would have taken at least 12 seconds, which, as Judy Wood has emphasized, is an astounding result that would have been impossible without extremely powerful explosives.
9) The towers are exploding from the top, not collapsing to the ground, where the floors do not move, a phenomenon that Judy Wood has likened to two gigantic trees turning to sawdust from the top down, which, like the pulverization of the concrete, the official account cannot possibly explain.
10) Pools of molten metal were found at the subbasement levels three, four, and five weeks later, an effect that could not have been produced by the plane-impact/jet-fuel-fire/pancake collapse scenario, which, of course, implies that it was not produced by such a cause.
11) WTC-7 came down in a classic controlled demolition at 5:20 PM/ET after Larry Silverstein suggested the best thing to do might be to "pull it", displaying all the characteristics of classic controlled demolitions, including a complete, abrupt, and total collapse into its own footprint, where the floors are all falling at the same time, and so forth, an event so embarrassing to the official account that it is not even mentioned in THE 9/11 COMMISSION REPORT.
12) The hit point at the Pentagon was too small to accommodate a 100-ton airliner with a 125-foot wingspan and a tail that stands 44 feet above the ground; the kind and quantity of debris was wrong for a Boeing 757: no wings, no fuselage, no seats, no bodies, no luggage, no tail! Which means that the building was not hit by a Boeing 757!
13) The Pentagon's own videotape does not show a Boeing 757 hitting the building, as even Bill O'Reilly admitted when it was shown on "The Factor"; but at 155 feet, the plane was more than twice as long as the 71-foot Pentagon is high and should have been present and visible; it was not, which means that the building was not hit by a Boeing 757!
14) The aerodynamics of flight would have made the official trajectory--flying at high speed barely above ground level--physically impossible; and if it had come it at an angle instead, it would have created a massive crater; but there is no crater and the government has no way out, which means that the building was not hit by a Boeing 757!
15) If Flight 93 had come down as advertised, then there would have been a debris field of about a city block in size, but in fact the debris is distributed over an area of about eight square miles, which would be explainable if the plane had been shot down in the air but not if it had crashed as required by the government's official scenario.
There are more, especially about the alleged hijackers, including that they were not competent to fly the planes; their names were not on any passenger manifest; they were not subject to any autopsy; several have turned up alive and well; tthe cell phone calls appear to have been impossible; on and on. The evidence may be found at st911.org.
) and I know what you mean about preparations, but I don't know enough about the structure of the WTC and whether there were weak points on each floor that would require only small explosive charges that could have been camouflaged as something else. Unfortunately the people who would have been in the offices and could shed some light on this aren't around to tell anyone. 