In the central area, where the statue is, a set of plaques would be located memorializing the entire 911 day in brief, including lists of DC and NYC deaths.
Ohhhh, I don't know. I think there should be SOMETHING to remember the terrorists who died on flight 93. Like, maybe their names engraved on the back of the urinals in the mens room there - to be used for "target practice". For privacy, the restrooms could be shaped like a 'crescent of embrace'. And, of course, don't forget the koran toilet paper. Of course, we should make sure the whole thing faces mecca!