"I was suddenly woken up by the earthquake."

"Everything was shaking."

"I definitely felt it!"

People in the San Francisco Bay Area shared their experience on Twitter about the earthquake before dawn on Sunday morning.

According to US Geological Survey (USGS), the 6.1-magnitude earthquake was centered four miles Northwest of American Canyon, California. Damage was centered in Napa County. Nearby cities including Napa, Vallejo, Sonoma and San Francisco clearly felt the quake.

The probability of a strong and possibly damaging aftershock in the next seven days is approximately 54 percent, according to an updated probability report released by the USGS. Most likely, the recent main shock will be the largest in the sequence. But there is the chance of an earthquake equal to or larger in the next week.

California Governor Jerry Brown declared a state of emergency for southern Napa County to allow all available state resources to be directed toward earthquake response efforts.

According to the emergency announcement, more than 69,000 residents are currently living in the area without power. The governor stressed the potential for aftershocks and fires as additional reasons for the emergency declaration.

"My office of emergency services has been on full activation since early this morning and is working closely with state and local emergency managers, first responders and transportation officials to respond," Brown said.

A spokesman for the Napa Fire Department announced that the city had already exhausted its own resources trying to extinguish fires and transporting injured residents.

The Chinese Consulate in San Francisco released a statement on its Facebook page Sunday noon, reading "Our blessings to those affected by this morning's earthquake! A strong 6.1-magnitude earthquake rocked the San Francisco Bay Area early Sunday morning, injuring at least 89 people in Napa. While the situation and rescues are still underway, we are trying to get more information to see if there were any Chinese citizens injured in the earthquake. We'll keep you updated, stay safe, everyone!"

China Enterprise Association (CEA) reminded Chinese overseas in the San Francisco Bay Area to pay attention to the aftershocks and contact CEA or Chinese Consulate in San Francisco as soon as possible if they need help.

zilian@chinadailyusa.com