9-11 could have and should have been prevented.
They had credible information that was either ignored or discounted.
Compounding this was the complete incompetence of airport security at that time (I suspect at this time as well) and their inability to stop the alleged hijackers from boarding. All of us who have to travel on airliners are paying the price for this now with the current idiotic regulations.
ALL of this has happened since the current administration was appointed.