In this instance we are talking of business resilience rather than the personal kind. Assess the risks your business faces, and the consequences of each risk. Some risks are quite likely, yet have a minor effect. Others are unlikely to happen, but the consequences can be devastating. Take action to reduce both kinds of risk, and plan how to deal with the aftermath. For example, if the office burns down, where will you relocate, how will you contact staff and clients?
A short post is not the right place to go into detail, but bear in mind that we are potentially talking about business life and death.
For an example of how one company keeps going through crises, see here for the Waffle House approach.