On Wednesday, a 4.2 magnitude earthquake jolted Northern California, triggering a 'ShakeAlert' throughout the area, unsettling residents.
At approximately 9:30 a.m. on Wednesday morning, the earthquake struck in the vicinity of the small community of Isleton in Sacramento County.
There have been no immediate accounts of injuries or property damage.
The earthquake on Wednesday occurred just one day before the annual Great ShakeOut, a global drill dedicated to testing emergency systems for earthquake readiness.
On Thursday, thousands of MyShake app users will receive a test earthquake alert as a part of this drill.
Coincidentally, the earthquake took place a day following the 34th anniversary of the Loma Prieta earthquake that shook the San Francisco Bay Area in 1989.
Millions of people were on high alert due to the notification that was sent from "USGS ShakeAlert" after the quake was felt by the San Francisco Bay Area suburbs.
"A longer part of the shake was initially detected, and that triggered a wider area that was alerted," said the director of the USGS' Earthquake Science Center in Los Angeles.