Well the source is CBS which wouldn't make sense for them to make things up.
Unless you're Dan Rather, right?
Anyhoo...
I think that anytime you have thousands die in a tragedy (especially when trapped and dying), you're bound to have a serious paranormal occurance.
Whether it's a dimensional rip, space/time rip, etc. who knows, but something is bound to result from it, even if only a strong psychic impression.
Heck, NO was one of the most haunted cities BEFORE the catastrophe, so I can only imagine what it'd be like now....post-Katrina....