So that flight and all its passengers just vanished? Maybe they are held in Gitmo? Or by now executed? Doesnt take much to melt aluminum. And of course burn plastic and fabric. For it to be true many 1000's of people would have to be in on it, before and after, and governments leak like a sieve. Especially ours. The longer it is the greater the chance of a verifiable leak.
The people that believe this shit do so because for individual reasons they want it to be true. So they pick that possibly might, because of a lack of information, and call anything that disputes them as fake. Which is convenient. If they cant prove it or disprove it they just say the coverup is really good. It is old and tiring. What's worse? People make money off of 1000's of dead Americans.