In fact, phone companies tend to drop charges for many calls as part of their contribution to disaster relief. In the California emergencies incoming long-distance calls were blocked in favor of outgoing calls. Congestion quickly emerged when too many people called from payphones. No network can be designed economically to withstand the gravest and rarest of disasters and congestions. This is not to belittle advance planning.
Disaster mitigation meets the prepared.
An emergency is no time to set up backup operations, fix a network, or create a database. Long in advance of disasters, the public should be educated on using telephones only minimally in such situations, and encouraged to pick a message meeting point. Collaborative agreements among otherwise competing carriers, such as exist in New York and California, should be reached and tested in advance. Mobile communications proved enormously helpful in bypassing destroyed landlines. But they, too, were vulnerable and congested.