9/11: Why Didn't the Pentagon Collapse?

I was at the beach yesterday with my brother, a Bush Hatin' liberal, discussing the various crimes of the Bush Administration. I told him the story of former Reagan Under Secretary of the Treasury Paul Craig Roberts who stated that Bush is making the same mistakes the Nazis did when they attacked Russia in the middle of winter. (You can read more here http:www.prisonplanet.com/articles/june2005/240605doubtstory.htm) Then I went on about how he also compared 9/11 to the Nazis burning the Reichstag and blaming the Jews.
"No, I don't believe it," Sean said dismissing every piece of evidence available presented before him. The owner of WTC 7 admitting they "pulled" the building due to extensive fire damage on the top floors. In order for that to happen, the building would have been wired with explosives well ahead of time. Why was it already wired.
I hit him with www.whatreallyhappened.com 's dog that did not bark. I suggest you go over there and read it, as the man over there tells it so much better than I. But my brother buys into the whole jet fuel/Arab thing.
"Oh, and I suppose they attacked us because we are free and they are not," I remarked rather caustically.
"No," my brother assured me, "They hate us because we have so much money and they don't have anything." Typical liberal. But before I could respond with "But Osama is a billionaire!" my attention was diverted by my oldest son just about to dunk his younger brother's head under the water and the issue drifted away.
Really, they hate us because we support Israel and let them systematically eliminate the Palestinian people from their land.
Last night as I lay awake, trying to sleep in this sweltering heat, it hit me. The one thing that proves that once and for all that the WTC were controlled demolitions.
The official story is: jet airliners, with tanks full of fuel, were crashed in to the twin towers, spilling burning fuel all over which caused the beams to weaken and the whole thing collapsed, conveniently, just like an implosion.
A third plane, with a tank full of fuel crashed in to the Pentagon. The only damage there was from the impact of the jet, the same jet fuel that caused the Twin Towers to collapse seemed to have no effect on the frame of the Pentagon! I'm sure it burned just as intensely, so why didn't it collapse?
At the time, I was employed with a company involved with the renovation of that building. We had people down there who saw the plane crash in to the Pentagon, clipping telephone lines on it's way. There was a plane with tanks full of fuel, but no beam melting fire.
So there you go, Sean. Explain that away. Becuase there are a whole lot more.