California Governor Jerry Brown has declared a state of emergency for southern Napa County after Sunday’s magnitude-6.0 earthquake.  Officials in the city of Napa are still assessing the damage.  They say 90 to 100 homes have been deemed not habitable, and there’s only limited access to many others.  The quake struck early Sunday about 6 miles from the city of Napa.  It ruptured water mains and gas lines, left two adults and a child critically injured, and upended bottles and casks at some of Napa Valley’s famed wineries.  The California Department of Transportation has inspected San Francisco Bay Area state highways and structures and says all damage appears to be minor.  The agency says bridges and roadways are open and safe for travel.  The earthquake is the largest to shake the Bay Area since a magnitude-6.9 quake in 1989.