In response to Mr. Ballantine's letter, I strongly urge you to do your homework about 9/11 before reciting such ridiculous conspiracies that have already been discredited by multiple sources. Just to help you out, I'll explain all your "theories" using an article titled "9/11: Debunking The Myths" from the March 2005 issue of "Popular Mechanics" magazine.
To start off, saying fire has never caused a building to collapse is flat out wrong. According to a survey done for the National Institute for Standards and Technology (NIST), six steel buildings have had fire-induced collapse. Yes it's rare, however, it has happened.
Also, you mention "intense fire melting the steel." This, in fact, did NOT happen. Jet fuel burns at a much lower temperature than that needed to melt steel. This caused the steel to lose its load-bearing strength. Too much weight on something with not enough support causes a collapse.
Lastly, when a plane hits a building reinforced to withstand a hurricane, like the Pentagon is, it's not going to act like a cartoon and punch a plane-like hole in the walls. In this case, one of the wings hit the ground and shattered while the other shattered upon hitting the support columns of the building.
Again, I suggest you do your homework and form your own opinions rather than believing the rhetoric babble of a notorious liberal radio host with no credit to his name. Look at things from both sides, not just one.