Thinking about it, a few points on gas prices...
1) 30 percent (around) of all gas refinery capacity is in the NO/LA area. How much of that capacity has been disrupted/destroyed and how long will it take to get said capacity back online?
2) All Refineries are pretty much running at capacity for summer season (and with the big travel holiday Labor day coming up).
3) The Strategic oil reserve would be perfect for the emergency, except there is no way to refine the gasoline. it's a psychological move to help keep the public calm until a better solution can be worked out.
4) Disruption of supply routes will become very evident in price increases as well as shortages that crop up with JIT inventory. (it won't be just in time if the trucks can't get through, the good news, the disruptions will be temporary as things get rerouted, unless railways have lost routes, those are a bit harder to get back up and running).
As far as calling this the big one or not, The story reminds me of a slow motion freight train hitting a car stuck on the tracks, no matter that you survived the initial impact, NO is going through the equivelent of being dragged along in the car and trying to get out before the car is totally destroyed. (My apologies for the rather gruesome analogy, it is apropos to the situation)
The flooding continues to worsen, You're now looking at issues of disease as well as any heat related risks. No city is ever a total loss, but New Orleans will be a very different city when it is rebuilt.
And I am not trying to mitigate what is happening over in MS and AL and NE of New Orleans. Their damage was more severe in quite a few ways.
I want to be wrong, I really do, and maybe if I say it, it'll turn out to be wrong (kind of like my storm predictions (gallows humor, sorry)), But I think the death toll will reach 4 digits and could reach 5 digits.
It may not be the 'worst case' scenario, but it's near enough to be indistinguishable from my viewpoint.
M. S. Earth and Atmospheric Sciences, Georgia Tech - May 2020. (Sigh LOL)