Nov. 13, 2008: Students of Stevenson Elementary School drop, cover and hold on during the region-wide simulation of an expected catastrophic 7.8 magnitude earthquake on the San Andreas Fault during the Great Southern California ShakeOut earthquake drill.
On Thursday at 10:21 a.m., a fictional earthquake gave Californians an opportunity to practice for a real shaker.
The faux disaster was part of the Great California ShakeOut (the one time a year Californians can actually predict an earthquake). More than 7.2 million people have registered for the event so far, making it the largest earthquake drill in history, according to organizers.
At exactly 10:21 a.m., participants were asked to "drop, cover and hold on."
"The main point is to not try to move, but to immediately protect yourself as best as possible where you are. Earthquakes occur without any warning and may be so violent that you cannot run or crawl; you therefore will most likely be knocked to the ground where you happen to be. You will never know if the initial jolt will turn out to be start of the big one," say planners.
The event started in 2008 but was limited to just Southern California. The event went statewide in 2009 and is now an annual tradition scheduled for the third Thursday of October each year.
Organizers offered tips catered to individuals, families, schools and businesses.