Millions Participate In Thursday's 'Great Shake Out' Earthquake Drill

LOS ANGELES (CBSLA.com) — Millions of Californians Thursday participated in the fifth annual "Great Shake Out" Earthquake Drill.

The 10:16 a.m. drill was the largest earthquake preparedness exercise in the U.S.

Participants were asked to drop to the ground, take cover under a sturdy surface and hold on as if a major quake were occurring.

The Southern California area "is highly susceptible to earthquakes and earthquake-related effects," the website ShakeOut.org warns. "Numerous earthquake faults crisscross Southern California and no one within the area resides more than 10 miles from an active fault. In addition to damage caused directly by ground shaking and related ground failure, other hazards such as fires can easily start during and shortly after an earthquake."

A large scale earthquake, such as a magnitude-7.8, could kill an estimated 2,000 people and would cause more than $200 million in damage, the U.S. Geological Survey said.

Californians should be prepared to be self-sufficient for 72 hours following an earthquake or other major disaster, officials said. All households should have a first-aid kit, and enough medications, water and food for each family member.