USGS Upgrades Bay Area Quake to 6.1

The city of Napa reported Sunday morning that dozens of people were injured, three critically, and several historic buildings were damaged in the 6.1-magnitude earthquake that struck near American Canyon.

The quake struck around 3:20 a.m. about three miles northwest of American Canyon, and was originally reported to have been magnitude 6.0.

“The earthquake occurred near the north shore of San Pablo Bay,” the U.S. Geological Survey reports. ”The bayshore areas in the San Francisco Bay region are underlain by landfill and bay mud and have experienced disproportionately greater damage during historic earthquakes. Such damage is caused by soil failure in the fills and amplification of ground shaking by the soft bay mud.”

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The injured patients are being treated at Queen of the Valley Hospital and an update on their conditions was not immediately available.

Napa city officials said the damaged buildings include the Napa County Courthouse, Goodman Library and Sam Kee Library. At least two commercial buildings were severely damaged in the quake, which also caused a fire that burned multiple mobile homes on Orchard Avenue in north Napa, city officials said.

There were approximately 50 gas line breaks and 30 water main breaks reported following the earthquake, causing some areas to have low or no water service.

The American Red Cross has set up an evacuation center at the Napa High School gymnasium at 2475 Jefferson St.

City officials said more information will be released at a subsequent briefing Sunday.

— Bay City News Service contributed to this report.

(Image via USGS)