It's dubbed the "Great ShakeOut." Thursday morning, schoolchildren, workers and first responders across the West and Southeast will practice dropping to the ground, covering their heads and holding on to something sturdy. Experts say the technique helps to minimize injuries in an actual quake.
Italy, Puerto Rico, Guam and British Columbia also signed up for the exercise, now in its fourth year.
Some 14 million will participate, up from 9 1/2 million from last year. Washington, D.C., Maryland and Virginia are joining in for the first time a year after a magnitude-5.8 hit that was felt along the East Coast.