Operation Cerebus was the German code name for the naval operation, on February 12th 1942, that saw three capital warships: Scharnhorst, Gneisenau, and Prince Eugen, race through the English Channel in broad daylight.
This daring coup de main was partially failitated by a cock-up on the British side. (There were lots of cock-ups that day, this one has educational benefits.) The British did have a plan in the event of a naval excursion into the English Channel. In fact it was a very detailed response, and as such it was a secret. A secret so precious that only copy in Dover, the main port on the Channel Coast, was kept locked in a safe.
On the day the plan was needed it just so happened that the officer who had the key to the safe was on leave in the South West of England, with the key! So the response to this daring foray was delayed whilst people made up a response on the spare of the moment. The resulting actions therefore were poorly coordinated and ultimately unsuccessful.
This piece of history has implications and warnings for project managers who have responsibility for disaster recovery plans. Too often these plans are outdated and nobody knows who has copies and where they are stored. Often the plans are stored on the very computer they are supposed to recover! An unavailable plan is the same as no plan!
So it is essential that you make sure everyone knows where the plans are, that they are accessible 24/7, and the correct people and their empowered deputies are available: Disasters don't recognize holidays, Public or otherwise.
Also the plans must be reviewed and walked through regularly. You don't want debates about what the plan means when your business is circling the drain. As a colleague of mine once said, "smoke coming out of a bank's data center is never a good sign".