Baltimore has a police force out of their control (it's in state hands) but they still have to pay for it. This has resulted in massive retention and recruitment issues, and some of the cops who did stick around were on the take -- specifically the Gun Trace Task Force, home of the locally-famous Jump Out Boys. Baltimore is an independent city, so it can't rely on county assistance for anything. Furthermore, state la…
> Furthermore, state law prevents Baltimore (and only Baltimore) from annexing suburbs to increase the tax base St. Louis is the other major independent city. The state doesn't restrict its ability to annex suburbs, but it hardly matters. It doesn't happen, anyway, and it almost certainly wouldn't in Baltimore, either. Who wants either city's problems?
It is unclear whether the PBGC (https://www.pbgc.gov/) will bail out the small municipalities. But i'd bet that Illinois, California, LA, NYC get bailouts. In such a situation, it would make sense for a municipality to join in with a "too-big-to-fail" entity.
I'm not a local government expert, but i'm seen enough bailouts to think these are decent guesses.