(The following was reproduced from the Amateur Radio Relay League's Web site at http://www.arrl.org/using-amateur-radio-in-an-emergency)
Help for the general public in emergencies
If your loved ones are in a disaster area, can you use Amateur Radio to contact them?
Since hams in a disaster area usually are very busy helping with immediate relief problems, it is usually very difficult to contact loved ones in a disaster area via Amateur Radio. But, it is possible. First, since hams in the disaster area may be called upon to assist local emergency officials, you should wait until the immediate crisis has passed and restoration efforts have begun. At that time, local hams may begin handling what is known as "health and welfare traffic." If you know a ham in your community, he or she may be able to enter a message into a traffic net which can then relay it to the affected site. The message should be brief (i.e. "Fred, We're worried. Call home, Mother"). Once received at the disaster site, your message may take considerable time to reach its intended destination since hams there may have no way of reaching your loved ones because of road blockages or outages in local telephone service. Do not pester your local ham to see if the message has been received. He or she has no way of knowing, and may be busy handling hundreds of similar messages.
In a disaster area, can you use Amateur Radio to get word out to loved ones?
Yes. But the first rule is, have patience. When disaster strikes, all lines of communication, including Amateur Radio, are overloaded. Amateur Radio operators in the affected area must give priority to supporting local emergency relief efforts. When the immediate danger has passed, most provide "health and welfare" communication traffic for local residents unable to reach a telephone. If you are in an affected area, locate an Amateur Radio station (often identified by a sign or banner) and leave a very brief message (i.e. "All is well here, love, John") address and telephone number for your loved ones outside the disaster site. Radio operators will put your message in line as part of their daily net "traffic" where it will be relayed via ham radio to the area where your loved ones live. Someone there may then be able to telephone your loved ones with your message. Since most hams are volunteers, most are unable to make long-distance calls on your behalf.