A former high-level intelligence official told me,
"Whatever trail was left was left deliberately--for
the F.B.I. to chase." New Yorker 10/1/01 by Seymour
Tracking the 19 Hijackers - What are they up to now?
At least 9 of them survived 9/11
For more, see http://www.welfarestate.com/911/#15