Fail-safe failures

The Machine promises to improve our lives, but what happens if the doors no longer open?

The other day, my wife and I were leaving our apartment building. I pressed the button which automatically opens and shuts the door. Nothing happened. We could not leave the building, except perhaps by jumping through a window. Eventually, the concierge, who happened to be outside, managed to open the door manually. He explained that there had been a power cut. The fail-safe system, which also worked electronically, had failed as well. The power cut lasted two hours.