There's whole movies made on this dude.
And books written.
You knew that, right?
https://youtu.be/MSyFD51vN_4
"Who Killed 9-11 Hero
John O'Neill?"
It so coincidental.. He was a whistle-blower,
It's another legend around the "event"
His body was never found. He was assumed lost there.
They got rid of him,
The FBI tied his hands in regard to his job which was tracking the "terrorist" / Patsy who were deliberately brought here and set-up the "catalyzing event"
He was likely an honest guy, not in on the plot.
He tried to do a good job and they cut his permissions; i.e. the permissions to really go in and check these guys computers , etc.
Why?
Because they were being handled already by the same FBI
"The Big Wedding" by Sander Hicks covers that aspect with some obliqueness [His Dad worked for the World Bank and he now running for office NYC]
O'Neill quit the FBI that summer. You know the rest.
Was made chief of security at the World Trade Towers.
First day of work, September 11th 2001