There is a good article on what should be done before using a facility after disaster occurs.The article quotes about list of safety tips from the American Society of Safety Engineers (ASSE) that should be considered following a disaster:
One should be more cautious and check twice all systems in place for using a facility involved in a disaster than a new facility as one does not know about the extent of damage and condition of building, services, equipment, piping, safety systems, etc. Outwardly, building may appear in good condition, but not actually. It is like entering a devil's cave. We have to do tests like hammer test, ultrasonic tests, etc to know about invisible cracks and disintegration inside the columns and beams.