People in government offices, businesses and schools throughout San Diego County will stop everything for a minute Thursday to "drop, cover and hold on" during a statewide earthquake preparedness drill, now in its 13th year.
The Great California ShakeOut of 2021 is scheduled for 10:21 a.m.
"What we do to prepare now, before the next big earthquake, will determine how well we can survive and recover," according to a statement posted to ShakeOut.org. "Great ShakeOut Earthquake drills are annual opportunities to learn and practice earthquake safety with millions of people."
The ShakeOut website indicated that 7.1 million Californians are slated to participate in the drill. During last year's event, which was virtual in most places because of the coronavirus public health lockdowns, about 6.5 million people statewide were registered to take part.
The exercises began in 2008.
"Southern California is a seismically active region and the best thing we can do about that is be prepared and know what to do," said Jeff Toney, director of the San Diego County Office of Emergency Services.
"Secure items to minimize or avoid injuries. And download the county's SD Emergency app to enable ShakeReadySD, which could give you a few seconds warning to seek cover during significant shaking."
In San Diego County, 529,328 people have registered for Thursday's drill. Municipalities on the list include Encinitas, National City, San Diego and Santee.
Parts of several other institutions are also signed up, including the county libraries, Naval Base Coronado, Goodwill Industries of San Diego County and Salk Institute for Biological Studies.
Cal State San Marcos, Grossmont Cuyamaca Community College District, MiraCosta and Southwestern community colleges, UC San Diego and the University of San Diego will also join the drill.
Most kindergarten through 12th grade school districts countywide, along with private and charter schools, will likely have students and staff participating.
According to ShakeOut.org, the objective is to emphasize precautions during a 7.8-magnitude or larger quake along the southernmost portion of the San Andreas Fault.
Officials say that such a tectonic shift could produce waves of movement for hundreds of miles, over four minutes. According to the U.S. Geological Survey, some 2,000 people would die, tens of thousands would be injured and more than $200 billion in damage would result.
The cataclysm would have 50 times the intensity of the Jan. 17, 1994, Northridge earthquake, which had a magnitude of 6.7.
Hundreds of aftershocks would ensue -- a few of them nearly as big as the original quake, according to the USGS.
In 2019, the drill came just over three months after the early July quakes that struck Ridgecrest in Kern County. The 6.4- and 7.1-magnitude shakers caused significant damage to roads and structures in the hamlet, which lies just south of the China Lake Naval Air Weapons Station.
Californians should be prepared to be self-sufficient for 72 hours following a major disaster. That includes having a first-aid kit, medications, food and enough water for each member of a household to drink one gallon per day, according to local and state officials.
Homeowners and renters should also know how to turn off the gas in their residences in case of leaks.
WATCH: Are you ready for the "Big One?" Great California ShakeOut to be held Thursday morning (October 2020)