Kincade Fire in Sonoma County Now Fully Contained

UPDATE: Cal Fire says a fire that was burning in Northern California in Sonoma County is now fully contained.

They said the Kincade Fire was 77,758 acres large.

The fire started on October 23 and the cause is still unknown.

Cal Fire says while there haven't been any fatalities, four first responders were injured.

They said 374 structures have been destroyed with another 60 damaged.

Original Story: The head of California's state firefighting force says weather conditions have improved and that authorities hope to begin containing a big wildfire in Sonoma County's wine country by nightfall.

California Department of Forestry and Fire Protection Fire Chief Thom Porter told reporters Thursday that the agency has moved this year to preposition trucks when fire conditions are dangerous.

He says that allows firefighters to quickly control fires and that only one out of more than 600 in the state over the last two days has become significant.

The Sonoma County fire broke out late Wednesday and exploded to more than 15 square miles (39 square kilometers) due to extremely windy and dry weather affecting the state. In Sonoma County, Porter said 100 firetrucks were ready to respond.

Earlier, authorities ordered the entire town of Geyserville to evacuate. 

The Sonoma County Sheriff's Office issued orders for immediate evacuation of the community shortly before dawn Thursday.

Geyserville has about 900 residents and is a popular stop for wine country tourists.

The fire erupted late Wednesday and exploded in size overnight to more than 15 square miles (39 square kilometers),

At least three homes have burned. There are no reports of injuries.

A statement from the sheriff's office says: "If you're in Geyserville, leave now."

More than 550 homes and roughly 1,700 residents are under mandatory evacuation orders as the burns without containment.

Sonoma County officials said more evacuations may be issued.

The smoke from the fire was so thick that the plume was captured on weather radar, according to the National Weather Service.

CNN contributed to this story.