Which parts do you want debunked (I don't have all day...). I'll go ahead and do the Pentagon one for you, since Abshalom mentioned it.
This is easy; I've been to the site of a plane crash before. It was an old World War II bomber which impaced the side of a mountain, fairly near the peak; they never cleaned it up (instead, they put a small memorial at the top for the pilots). The place is remote; you can't get there by car, and even if you could get a motorcycle to the peak (doubtful), I doubt you could get a motorcycle up the side of it (it was about a 45 degree grade the whole way up, and was rocky and thickly forested (so you couldn't just roll or toss things down without a lot of effort), so there's no way visitors could carry any remotely large piece of debris away from the site without something like a helicopter.
You start to hike up the mountain. About halfway there, you see your first piece of debris. You expect to soon be encountering a large debris field, but it eludes you. There's lots of small debris that you keep encountering - often, little more than scraps of metal - but you never seem to hit the large debris. You keep going; the largest thing that you have passed thusfar is little bigger than a twisted propellor. Near the top, you get into some pieces no bigger than a motorcycle, but you're still waiting to see that debris field. At the top, the trees clear... and the only large piece that has remained in tact over the course of the hike, apparently, is up there: 2/3rds of one wing, attached to a tiny piece of fuselage.
What happened to the rest? As I was thinking about that, I stopped to look down, and noticed that there were aluminum nodules - everywhere. Thinking back down the hill, there were also tons of tiny scraps. The answer was simple: the impact of the plane literally ripped it to shreds, and the subsequent fire melted many of the pieces at that weren't blown away from the main impact site.
I'm actually surpised to see *as much of the airplane survive* as did at the Pentagon, not the other way around. Airplane crashes are incredibly violent events.
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"Illuminant light,
illuminate me."
[This message has been edited by Rei, 12-12-2003]