A lot of big retailers have been overstretching themselves (not exactly the right phrase, but the meaning is clear I think) for years. The list could easily be a lot longer than 15, though that's not clear just yet.
It'll become clear next month- the rents are due on most of the stores. These big sales are mostly to make rent money.
Two things of note: Many of the Woolies stores are selling their fittings (i.e. the shelves) as well in what one paper termed "a very British form of looting" and people are buying their presents for
next Christmas.