A 5.6-magnitude earthquake hit near Mendocino County early last week.
The quake echoed through Northern California in the region.
Phones across the Bay Area blared with ShakeAlert warnings.
The shaking hit San Francisco and adjacent locales.
Reports say minimal damage showed up immediately after.
Officials remain on alert for aftershocks.
They urge people to stay ready as a precaution.
5.6 earthquake reported in Northern California, triggers alert across Bay Area San Francisco Chronicle
Shake alert lights up Bay Area phones Wednesday morning after 5.6 quake hits Mendocino KRON4
Magnitude 5.6 earthquake felt across Northern California, USGS says KCRA
Northern California hit by magnitude 5.6 earthquake in Mendocino County CBS News
Magnitude-5.6 earthquake shakes parts of Northern California NBC Los Angeles