What you are really talking about is called "Cascading failures". During my days in the Air Force there was a great deal of time spent on this phenom. In modern jet aircraft (as happens in computers, servers, etc.) when one system fails it can put a load on another or fail on other components that are dependant upon the intial component.

The strangest aspect of cascading failures is that they are extremely common, not only in machines but in the human body as well, and yet we tend to think that one thing fails most of the time - and we create plans around that scenario - only to find that in actuality, when one thing breaks, others follow.

Any good recovery scenario should plan for cascading failures, NOT single instance failures. In my experience in this business, companies that plan for one thing to break usually wind up lost when a batch of things go down. On the other hand, companies that plan for cascading failures are much better positioned to recover and maintain productivity.

The lesson? Plan for the more common instance - not the rarer instance.