I know for fact, that one of the WalMarts being closed is a bonifide ghetto mart.
Hookers, druggies, and strip joints surround it.
I assumed the plumbing issue was guns and needles clogging the pipes.
One closed around here a few years ago near the edge of fragile neighborhoods. They had another reason, but some said that store had a huge problem with theft.
Just another hypothesis to throw into the mix: Maybe after what happened in Ferguson last year, chains might be wise to close stores now in areas that are candidates for chaos.