Hundreds more firefighters have been called in as a wildfire burning in Mt. Diablo State Park nearly doubled in size to 1,500 acres Monday.
Approximately 100 homes and other structures have been evacuated as a precaution as bulldozers and hand crews worked to build containment lines around what's been dubbed the Morgan fire in Contra Costa County, said Cal Fire staff chief David Shew.
Containment of the blaze remained at 10% Monday morning.
An additional 500 firefighters were called in to assist more than 300 personnel already assigned to the blaze, Shew said. As of Monday morning, crews had eight miles of containment lines still to build in order to contain the blaze, he said.
"It's going to be a pretty big battle to build all those control lines," Shew said.
Crews were dealing with steep terrain as air tankers and helicopters dropped water from above. Low humidity and dry brush were fueling the fire's spread, Shew said, and "pretty erratic winds" that have a history of blowing around Mt. Diablo were hindering the firefighters' efforts.
Evacuations ordered for Oak Hill Lane, Curry Canyon and Curry Point remained in effect Monday morning. An evacuation center was set up at Clayton Community Library in Clayton.
Marsh Creek Road was also closed at Regency Drive in Clayton, officials said.
The cause of the fire was under investigation.