More than 10 million Californians are expected to "drop, cover and hold on" Thursday morning as part of a worldwide exercise in earthquake preparedness.
Started in Southern California in 2008 by the U.S. Geological Survey, the Great ShakeOut Earthquake Drill is expected to draw more than 17 million participants nationwide this year.
At 10:20 a.m. local time Thursday, students, seniors, troops and others registered for the drill are set to practice the mantra of "drop, cover and hold on."
The public-private partnership Earthquake Country Alliance says 10.6 million people in California will take part.
Taking a tumble or being struck by a falling object are perhaps the two greatest hazards during an earthquake.
It's recommended that people who are indoors during a temblor drop onto their hands and knees, take cover under a desk or table and hold on.
People outdoors should try to hunker down in an open area away from power lines, trees or buildings. Drivers should pull over to the side of the road, set the parking break and remain in their cars. Taking shelter under bridges is not advised.
Earthquake experts have long struggled to get the public to focus more on the risk of a devastating temblor.
Smith writes for the San Diego Union-Tribune.
8:20 a.m.: This article was updated with details and links on "operational earthquake forecasting."