As one who at one time worked in casino management in NOLA, can only tell you that it was due purley to incompetence and corruption in all levels of the state and city government, the likes of which I had never seen before - so many commentators seem to be uneducated on LA, or being PC; comments like '(NOLA) is now like a 3rd world country.' Beleive me, it was like a 3rd world country and run like a banana republic long before this tragedy.
Lived there 18 years, sad but true.
The pattern was set by Governor Huey Long in the late '20s and early '30s and continues all the way through. I don't know who took Carlos Marcellos' place as Mafia Don down there but I am sure someone did.