Schoolchildren practice their "drop, cover and hold on" technique, in the biggest ever US earthquake drill in California.
More than five million people took part in the exercise. These student volunteers from Mission Hills, Los Angeles were made up as earthquake victims.
These Los Angeles firefighters were among some 5,000 participants from dozens of state, local, and federal agencies who took part.
The drill was based on the hypothetical scenario of a magnitude 7.8 earthquake. LA high school students protect themselves from falling items as they experience a "tremor".
Schoolteaching assistant Maria Williams helps evacuate student Ellis Blaton, 4, who is pretending he has a sprained ankle. Experts believe another huge earthquake in California is inevitable.