[Yeti]

Odd that the post should have sat around for a month and then you both post replies the same night...

just_living, you seem to have a kinder historical explanation than the one Bernard Marx offers, though you both have the police factor in common. I'll go with Bernard Marx's, since he can cite a source.

And I'll stick with my assessment of the town: it's an insane asylum.

[Bernard Marx]

And I'll stick with my assessment of the town: it's an insane asylum.

No argument there!

[just_living]

Not so odd, I did a search on San Francisco, and posted two replies.
The thing that makes me think my explaination is right is that many cities not just SF have a tenderloin district.
Sources are hard to come by (and what exactly was his source, I don't see it), but here is one (albeit they say there is no source):
A number of cities in the U.S. have "tenderloin" districts. Legend has it that these rough-and-ready neighborhoods got their nicknames from the police who patrolled them; these cops received hazard pay (or bigger bribes -- stories vary), and were therefore able to regularly dine on steak.
http://www.wikitravel.org/article/San_Francisco/Tenderloin?PHPSESSID=169ed8c53701108085fe62dec436a1b2