NAPA, California - 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 (10 kilometers) 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.