The drill took place at 10:16 a.m. More than 10 million people across the state, including 4 million in Los Angeles County alone, were registered to participate.
A simulation drill was held at Biola University in La Mirada, mirroring what would happen in the event of a 6.7-magnitude earthquake.
"It'll be a lot of chaos, a lot of people screaming, a lot of people in agony, bookshelves tilted over. Anything that wasn't bolted down would be on its side or tilted against a wall, maybe some light fixtures are dangling, live wires out there," described Capt. Tom Richards with the Los Angeles County Fire Department.
The Great Shakeout started seven years ago in California.
Organizers want you to be ready. Have emergency kits inside your home and car with batteries, flashlights, medical supplies, food, water and cash, in the case that ATMs are not available.
Of course, earthquakes cannot be predicted. But according to seismic experts, there is a 97 percent chance a quake with a magnitude of 6.7 or greater will strike California within the next 30 years.
"It's a shock to anyone, going through this. You're going to be taken back for a second. What we want people to do is know what they need to do, so they need to practice so you're not panicking and doing the wrong thing," said Leslie Luke with the Office of Emergency Management.
Some misconceptions include standing in a door way or running outside.
"That's what the Great Shakeout is all about - us practicing and preparing. It will help subdue some of those fears," said Richards.
Officials recommend that you speak to your neighbors, so you can build a community response ahead of time.