September 11: The Intent
What we should remember is the intent of Al Queda. Not only did they target and bring down the two towers, I think it's pretty clear that the Capitol and The White House were the other two targets. Poor navigation and the heroes of United flight 93 left both standing while the Pentagon became a secondary target. Imagine if they had succeeded, or now succeed on a larger scale, with a dirty bomb in a harbor somewhere for example.
The body count in New York could have also been much higher, if the towers hadn't stayed up as long or had not pancaked almost straight down. In fact, go back to the 1992 bombing that came uncomfortably close to toppling at least one of those towers onto the New York streets.
There is no limit to the carnage that these Islamic terrorists would inflict on us if they could. We must remain vigilant. The 3,000 we lost then and those since then serve to remind us of the stakes.
We must never forget.