Here's a similar kind of story and one that I found very interesting. It comes from Rob Lowe's book Stories I Only Tell My Friends in which he talks about how he got bumped to an earlier flight a week before because of filming schedule and how he was in fact suppose to be on one of the 4 planes that went down. Not only that, it was also discovered that the week before 9/11, he was on THE flight were the terriorist were on the same plane as him, used as a test run to see how it would all transpire.

That gives me goosebumps to even think that your on a plane full of terrorist and don't even know it because, in Rob's words, they all looked like normal every day people.