Disaster officials held an earthquake simulation in Menlo Park Monday as part of the preparations for Thursday's statewide earthquake drill, known as the Great California ShakeOut.
Disaster officials are trying to get people to think about what to do before and during the next earthquake.
Monday's demonstration stressed the idea of drop, cover and hold on, in other words to get on the ground, get under something stable and grab it.
The exercise came a day after the anniversary of the 1989 Loma Prieta earthquake.
That quake killed 63 people and injured more than 3,700 others.