I guess it depends on what qualifies as a city. I personally don't believe any place that has less than 250,000 within its borders proper qualifies as a city. So that takes out all the small little towns in the U.S that people rag on (and it makes sense, they are usually low population wise for a good reason).
That being said, worse city would in the U.S would almost certainly go to either Indianapolis or one of either Cleveland, Cincinnati, or Columbus. The problem with Indianapolis is that its incredible boring with no redeeming architecture and it's devoid of street life or any culture at all. Such a terrible generic city. With the cities in Ohio, it's just that the jobs all went away and they are a former shell of what they once were. Columbus is able to maintain but just barely and that is majorly due to Ohio state university anchoring the city.
Truth be told, every state in the U.S is filled with sketch depressing places. I personally believe that the Midwest contains the most of these places. When you mix in flat land with very little scenery, old towns that are devoid of life and all jobs are gone (looking at you state of Indiana), no real culture, super segreagation, bland food, yearning for the good ol days, and lack of real transit, you get the worse of the worse. There is a reason the Midwest is known as flyover country. In truth, aside from Chicago (and maybe it's extended megalopolis up to Milwaukee), the twin cities, and maybe, maybe Madison Wisconsin, the rest of the Midwest cities are extremely depressing. I do believe there is hope for Detroit to return to its former glory. It'll take a long while, but I believe it will happen eventually.
