Major Earthquake Shakes Northern Calif.

NAPA, Calif. (AP) -- Gov. Jerry Brown has declared a state of emergency for the part of California's wine country hard-hit by a large earthquake.

The governor issued a proclamation directing state agencies to help respond to the 6.0-magnitude quake that struck early Sunday about 6 miles from the city of Napa.

Napa Fire Department Operations Chief John Callanan says the city has exhausted its own resources extinguishing six fires, transporting injured residents, searching homes for anyone who might be trapped and answering calls about gas leaks, water main breaks and downed power lines.

Callanan says three people are reported to be in critical condition, including a young child who was struck by part of a fireplace and airlifted to a specialty hospital for a neurological evaluation.

Inspectors are evaluating damaged buildings, bridges and roads.

The largest earthquake to hit the San Francisco Bay Area in 25 years sent scores of people to hospitals, ignited fires, damaged multiple historic buildings and knocked out power to tens of thousands on Sunday.

The 6.0-magnitude earthquake that struck just before 3:30 a.m. miles from Napa in California wine country was felt widely, breaking water mains, causing more than 100 gas leaks, leaving two adults and a child critically injured, damaging some of Napa Valley's famed wineries, and sending residents running out of their homes in the darkness.

Dazed residents too fearful of aftershocks to go back to bed wandered through Napa's historic downtown, where the quake had shorn a 10-foot chunk of bricks and concrete from the corner of an old county courthouse. Bolder-sized pieces of rubble littered the lawn and street in front of the building and the hole left behind allowed a view of the offices inside.