According to the tinfoilers, they were all taken ioff the planes, consolidated into a fifth plane and then flown to a secret location somewhere in the Rockies where they are being held as prisoners of the government.
So, they'd kill 3000 people at work in office buildings, but they'll keep a few hundred alive who know the whole thing was a sham, and have to house, clothe, feed, etc., them?
Brilliant minds at work underneath all that tinfoil.