According to the New York Times, this shock woke up many residents in the middle of the night, causing them anxiety and preparation for possible secondary shocks. The Bay Area Rapid Transit fast transport system released trains to carry out security checks.
Sejsmologists from United States Geological Survey (USGS) are still analyzing data, which may result in magnitude update and shock intensity maps.
The earthquake hit California
The last large earthquake in San Francisco, with a magnitude 6.9 took place on October 17, 1989 in Loma Prieta. Caused 63 fatalities.
USGS provides another large earthquake in the San Francisco Bay in the next 30 years. There are 72 percent chances that he will reach a magnitude of at least 6.7. However, the exact date and size cannot be precisely predicted.
