"Technical issues following power system interruptions mean that data held on computers in the central data centre for the region cannot be accessed. The nature of the incident meant that service could not immediately be provided by the back-up systems."
If that happened to my web server I would want to be asking some very serious questions indeed.
Such as: why did the back-up power systems not come onstream as soon as the main power supply failed?
Was there a disaster recovery policy in place in the data centre, and if so, did it include regular simulations designed to test for just this kind of incident?
One would hope that a modern system costing £6.8 billion over ten years would be just about bomb-proof as far as powers supply failures were concerned. If I was managing such a project it's about the first thing I would want to get right.