At 10:18 a.m. Thursday, government officials and children all over the valley will start acting weird.
But don't panic. It's an earthquake drill.
The exercise is part of a worldwide earthquake preparedness effort called the Great Shakeout.
"Knowing what to do when the floor starts moving will save lives, and the very small amount of time spent participating in drills will make a difference in an emergency situation," Paul Gerner, the Clark County School District's associate superintendent of facilities, said in a news release.
According to the seismological lab at the University of Nevada, Reno, the Silver State ranks third in the nation for the number of large earthquakes over the past 150 years. Since the 1850s, Nevada has seen 76 earthquakes with magnitudes of 5.5 or more.
To help prepare, the governments of Las Vegas, Henderson, North Las Vegas, Clark County and the Clark County School District have banded together this year to participate in the effort. Others statewide also are participating, including every school district in Nevada.
"Everyone in Nevada needs to have a plan and practice for an earthquake," said Graham Kent, director of UNR's seismological lab and lead organizer of the Nevada drill.
More than 500,000 Nevadans have registered to participate, including 360,000 in Clark County. A dozen other states also are holding events.
Worldwide, 18 million people are expected to drop, cover and hold on.
During an earthquake, people should drop to the ground, hide under something sturdy and hold on to whatever they're hiding under so that it doesn't move away from them.
The U.S. Geological Survey says that if you're not near a desk or a table, you should get on the floor against an interior wall and put your arms over your head to protect it. Avoid exterior walls and hanging objects such as pictures and mirrors.
Contact reporter Richard Lake at email@example.com or 702-383-0307.