This prophecy speaks of a time when malls will lay more than half empty, and stores and strip malls will remain closed with no one leasing the buildings.  This will lead to the owners being unable to pay their debts on the properties that will create debt problems with the lending institutions.

EDIT (2019-04-24): While I don't have a second prophecy or source to go with this, other than the one that John Paul gave, the more I'm seeing, the more this seems to indicate that this is just a subset of the actual global economic collapse that's coming, as well as a much wider retail apocalypse that will precede it.  Which, that's pretty much what this "death of malls" prophecy is, is a much narrower view of a much wider issue.  Namely, the collapse of retail.