The Great California ShakeOut of 2024 took place at 10:17 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 a once-a-year chance for everyone to practice drop, cover, and hold on' and learn other earthquake safety tips."
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The ShakeOut website indicated that as of Wednesday afternoon, more than 10.5 million Californians were participating in the drill, including 3.4 million in Los Angeles County and 954,000 in Orange County. During last year's event, about 10.2 million statewide registered to take part.
The exercises began in 2008.
Municipalities whose local government employees were involved included El Segundo, Arcadia, Calabasas, Lakewood, Lancaster, Hawthorne, Glendora, Costa Mesa, Lake Forest, Buena Park, Torrance, Paramount, Santa Clarita, Seal Beach, San Clemente, Brea, Garden Grove, Newport Beach, West Hollywood and Monrovia. Multiple Los Angeles city and county departments and Orange County agencies are also registered to participate.
Virtually all elementary and high school districts took part, along with California State University and Los Angeles Community College District campuses, UCLA and USC.
The Metrolink commuter rail system also took part in the drill, with all trains slowing at exactly 10:17 a.m. in response to a simulated earthquake. The Orange County Sheriff's Department also used the drill to test its emergency mass notification system, AlertOC, at 10:17 a.m., sending a test emergency message to mobile devices and home phones.
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 believe 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.
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Hundreds of aftershocks would ensue -- a few of them nearly as big as the original quake, according to the USGS.
The drill in 2019 came just over three months after the July quakes that struck Ridgecrest. 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.
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