I had the misfortune to attend a science conference in downtown Detroit in the mid-1980's. Place scared the crap out of me far worse than pre-Katrina downtown New Orleans ever did. Also did some conferences in downtown Chicago in the same time frame, and the "vibes" weren't nearly as bad.
Going east of the Chrysler or West of the Lodge is another matter.
Funny you mentioned New Orleans. They are the number four highest gun murder city in the US.
rwood