Once you get outside the conventional narrative for September 11, 2001; once all the inconsistencies and the anomalies are catalogued - probably the hinkiest thing about it is the simplest.
Every time someone in an emergency calls 911, every time someone tells their children if anything bad happens to call 911, every time you see a service vehicle go by close enough to read the decals and logos - there it is again and again, linked to disaster, catastrophe, trouble, and the presence of authority.