A system already used in California and Oregon, called ShakeAlert, went live in Washington, but third-party apps, which are faster, aren't available there yet.

The new system, which Gov. Gavin Newsom called the first of its kind in the U.S., will notify residents up to 20 seconds before the shaking starts.

ShakeAlertLA runs on data collected by a network of seismic sensors designed to give residents precious seconds to brace themselves for major tremors.

A new law passed by the Los Angeles City council would enact stronger standards for cell phone towers in an attempt to protect networks during an earthquake.