10 people killed in California's wine region by fast-spreading fires in the United States. <br/><br/>Authorities said 7 people were killed in Sonoma, two in Napa and one in Mendocino counties when a spate of wildfires fanned by strong winds swept through northern California's wine country on day. <br/><br/>Authorities also said about 20,000 people fled from these counties after state's worst-ever wildfires broke out. State officials said, two hospitals were forced to evacuate in Sonoma County. <br/><br/>The head of California's Department of Forestry and Fire Protection, Kim Pimlott, said that about 1,500 buildings had already been destroyed in the fire. <br/><br/>The Governor of California, Jerry Brown declared a state of emergency for Napa, Sonoma,Yuba and four more northern California counties as well as Orange County in Southern California. <br/><br/>Spokesman for the Governor's Office of Emergency Services,Brad Alexander, said the death toll could climb higher.<br/><br/>The National Weather Service has issued a warning for the San Francisco area that any fires that develop will likely spread rapidly.<br/><br/>