Google has a program called DiRT (Disaster Recovery Testing)[0], when in a certain week of the year, some major exercises that simulating the loss of headquarters are carried out, including the (simulated) loss of some teams, some network connections in the headquarter and/or the physical access to the headquarters buildings. That makes a lot of sense when you place your headquarters at a place that can be demolished by an earthquake.
That is actually an excellent idea. Loss of manpower is something that is overlooked in a lot of companies. I believe part of it is job security (make yourself invaluable). And part of it is HR optimisation. Why pay for 2 people to do the same job when 1 will do? The same reason you pay for 2 servers, 2 backup processes, etc.
[0]: http://queue.acm.org/detail.cfm?id=2371516