Funnily enough, I came into a company shortly after it had experienced a major network outage due to some bad configuration. They had backup files from which they wanted to restore the original configuration which, of course, were stored only on the network that was experiencing the major outage - and they were thus unable to get to them. In many companies management is in-band, which makes things more challenging in a crisis.
In a similar vein, even having multiple copies of your data might not be enough. One of the things I have said in the past is that when considering Business Continuity and Disaster Recovery (BC/DR), too many people focus on the DR part and forget about the BC bit - i.e. how are your employees going to be able to access that DR infrastructure when the primary site is down?