For what its worth...
...I believe Mr. Bush was essentially asleep at the switch during the first nine months of his administration. After 9/11 he appears to be wired on NoDoze.
That being said, its wrong to blame 9/11 on either the Bush or Clinton administration. It was an act of terrorists, committed by terrorists on behalf of terrorists.
Likewise, its wrong to blame Mr. Giuliani for the chaos that ensued when two jetliners filled with aviation fuel struck two tall skyscrapers filled with thousands of people. The circumstances are implicitly chaotic.