St. Louis is arguably the worst case of urban decay currently occuring in America, even worse than the much popularly maligned Detroit.
Basically, there are whole districts of the city that are just literally falling apart. The city’s population has been shrinking, poverty is rampant as the economy tanks, public services are on the decline…
Vice has a documentary on it.
Edit: For comparison, heres St Louis crime statistics compared to by far the most dangerous city in Ecuador (currently only in Western news for their war against cartels).