No big groceries in Detroit?

A segment on Marketplace tonight stated there are no supermarkets within the boundaries of Detroit? Is that possible? It’s an interesting story about turning vacant land – there’s no shortage of that in Detroit – into gardens:

I saw a fella going down the street on a tractor. So, being a farmer, I flagged him down and said, “Man, what do you do with a tractor in the city?” And he said, “Well, I make $100,000 mowing weeds on vacant lots.” And I got to thinking, “Man, if we take that money and turn it into growing food on vacant lots….”