If a magnitude 7.0 earthquake really were to occur, state officials have placed the projected death toll for the nine counties along the Wasatch Front at about 2,500 people, with about 2,000 would suffering life-threatening injuries.
This is the second annual ShakeOut.
In 2012, Utah had the largest per capita participation ShakeOut in the world, with 33 percent of the state's population, or 945,000 Utahns, involved in the mock quake.
Last year's participants included private citizens, schools, hospitals, grocery stores, the American Red Cross and the Utah National Guard all monitored by the Emergency Operations Center in the basement of the state Capitol.
It was a learning experience for everyone.
Officials found that communications between state agencies needed improvement.
Families and workers learned simpler life-saving lessons, including that rather than taking refuge in doorways (as was previously thought was the best strategy), participants dropped, covered and held under desks and tables.