California conducted a test Wednesday of the tsunami warning communications system as part of Tsunami Preparedness Week.
The test came four days before the 52nd anniversary of the 1964 Alaska earthquake and tsunami that caused millions of dollars in damage to the California coast and killed 12 people at Crescent City.
Read: How the System Works
The National Weather Service and California Office of Emergency Services transmitted tsunami warning codes in Del Norte, Humboldt and Mendocino counties between 11 a.m. and noon via NOAA All-Hazards Radio, the Emergency Alert System, TV and radio stations.
In Southern California, the system was checked at 10:15 a.m. as a "required monthly test" message via NOAA radio and TV and radio stations. Some television systems were programmed to scroll a standard message indicating the broadcast is a test along with an audio message also saying that it is only a test.
County officials urged residents to be prepared for natural disasters such as earthquakes and tsunamis.
"A first step is to find out if you live, work or recreate in a potential tsunami inundation zone by visiting TsunamiZone.org," said Jeff Reeb, director of the county's Office of Emergency Management. "In addition to knowing what are tsunami warning signs, keep yourself and your loved ones safe by developing a family emergency plan."
Residents can also connect with local officials to organize a "tsunami walk" or evacuation drill.