Even if evacuation is not called for, there are many possible scenarios that may result in the temporary separation of family members.
For example, in October, 2002, the DC regional sniper crisis resulted in several occasions in which the police authorities suddenly closed major interstate and secondary highways. These road closures affected many thousands of people, sometimes preventing them from traveling anywhere for six hours or more. Undoubtedly, very many families suddenly experienced the sensation of not knowing whether their family members were safe, and were forced to deal with children being stranded at schools, sports practices, martial arts studios, dance lessons, etc.
In these kinds of cases it is essential that everyone involved know what to expect from the other family members, especially children. It is important to discuss where everyone will try and meet up when conditions permit, and what communications methods will be used. The meeting place would normally be your home, of course, but an alternate location must be pre-selected in case that primary location is unreachable.
In the case of children, plans must be pre-arranged if alternate adults are expected to accept responsibility for them while the parent(s) are prevented from making their way. The conditions for picking up or accepting responsibility for children must be quite clear, because it must be expected that normal telephone communications are impeded or blocked by the crisis. Schools have formal policies regarding who is allowed to pick up children from school, but other organizations, such as sports leagues or dance studios, may have no formal policies or very lax enforcement.