I remember seeing all those places, I grew up in Detroit and didn't move out until a year after I married.. At that time, to buy a house in the city was more expensive than buying in a new suburban sub-division. It sure isn't like that anymore...Detroit was once a beautiful place. Many called it the Venice of the country...You wouldn't believe that looking at it today...
Example: The first house we bought after marriage was a 3 bedroom ranch about 20 miles N. of Detroit and it cost only 13,900.00 sticker shock: That was in 1960.
You couldn't buy any home in Detroit for that amount of money....its sad what has become of that place...
If parkland is the intended use, then concrete and basements present no problem; collapse the house into the basement, dump on some broken sidewalk concrete and asphalt, cover with topsoil, then seed. There will be settling, contamination, etc. (which is already there); it’s been done in other places, and nobody’s hurt in the end. The eyesore goes away, and an area that certainly has plenty of other industrial problems in its soil returns to nature.
I’ve heard Detroit referred to as the first American city with bona fide “ruins” (along the lines of the Acropolis). Whatever they do with it has to be better than leaving humans in it at this point. Like other areas where this has been done, you can take the most historical and/or structurally sound buildings and use them as a visitors center, museum, park ranger headquarters, etc.; the most contaminated areas become parking lots with 3 feet of pavement between the car tires and the soil.
I know this stuff; I’m from New Jersey! : )