There was an article in the Post a couple months back that average home values in Baltimore have fallen to $10K. Hard to believe that is possible.
They need to do what some other cities have done. Enforce property tax collections. Foreclose on properties for which taxes aren't paid within a reasonable amount of time, and demolish any blighted ones foreclosed on in this way. Over time the housing stock shrinks while nuisance properties are eliminated, and the city is positioned to once again grow once the excess stock is removed.