I knew a guy who grew up in the city...and went back two years ago. In 10 minutes, he saw 40 houses that were abandoned. You have whole streets where half the homes are empty. Its unlike any major city in the US.
Youngstown, OH is a mini-Detroit in that aspect.
What is bizarre, is it used to be one of the finer cities in the country, apparently. The houses are beautiful. My own hometown suffered a similar if much smaller condition. What started it were the riots in the 1960s, believe it or not, and we have never completely recovered. The downtown is virtually a ghost town, and huge pre-depression era houses sit empty, crumbling and decaying. It’s like visiting another abandoned planet, and you’re struck wondering “who were these people to make such wonderful edifice, and who were we to let it all slip away.”