Not by authorities but by a ground zero worker, me.
911 was about kicking Christians (the Irish - Cantor Fitzgerald) out of finance by Jews and Saudis.
Because a good crisis is never let gone to waste, all other conspirators planned all other crimes around it, pentagon budget, gold in the basement, insurance on the building, etc…
Alwaleed Bin Talal , Citi, was the mastermind.