NatWest bank+RBS debit card/wire transfers down (not just a social network)

The HN discussion about the Twitter story was "twitter doesn't lose any money when they're down for 2 hours, so full uptime isn't essential". So what happens when a bank's wire transfer and debit card infrastructure is down for a day or more? Could they afford the fix that would prevent it? Will they publish a report on what went wrong and how they'll prevent it in the future? Seems much more interesting to me...