I always felt like The Walking Dead was missing an opportunity to do some good.
Years ago I read about a movie production crew that got permission to demolish a rundown public building as part of filming in exchange for rebuilding it afterward.
For TWD you could use several of those abandoned Detroit neighborhoods for a sequence and then bulldoze the neighborhood to the foundations afterward, reducing the health and safety concerns.
There are a few auction sites online, I believe the city runs one or two of them. The thing people miss on these is their annual taxes, which are not forgiven, as well as the near instant requirements to meet livability standards (reno) lest they be fined. There's a lot to it that's over looked. As they say, no such thing as a free lunch.
A lot of those ads seem to think that anyone would buy those homes to renovate them. Tearing them down seems to be the smart decision, if you could even consider buying abandoned Detroit homes smart. One of them has fire damage throughout the home, literally holes in the roof from the fire. Ad calls it a "handyman special".
There's a reason they're being given for free...