The ladder leading out of the bar section of this area is in Hotel California mode. It's by default locked, so you can only check out any time you like, but you can't leave.
This doesn't appear to be locked in the toolset, possibly you stumbled in after a DM locked it for some reason? Is this still an issue?
I'll check next time I'm able if it is so. Yesterday the door into that part of the sewer was locked so I could not enter at all. I.e., I don't have my spawn point there.