There's an interesting blog maintained by an employee of a New Orleans ISP who stayed at their center, located in the CBD, throughout the disaster and kept it running.I don't know New Orleans geography, but it sounds like he must have been close to the BellSouth "main" facility on Poydras, as he mentions it at least once
On Thursday Sep 1 he says
We've got a prayer! Huge convoy of fuel and generator engineer types affiliated with Bell South just moved down the street toward their building. That's where 2 of our OC3s that went down are at Bell's main.