Check this out; the 9/11 Commission may have been bribed.
On Jan. 28, 2002, CBS Evening News, quoting multiple sources, reported that on the night before the Sept. 11 terrorist attack, Osama bin Laden received kidney dialysis treatment in a military hospital in the garrison town of Rawalpindi, just outside Pakistan's capital Islamabad. The report quoted a medical worker who wanted her identity protected, saying that some Pakistani troops "moved out all the regular staff in the urology department and sent in a secret team to replace them" with the aim of treating a "special patient."
Lots of good info there, most notably:
There is evidence some ISI officers may have known of a plan to destroy the WTC as early as mid-1999