Ventura, California (CNN)Tens of thousands fled their homes Tuesday as several incredibly fast-moving brush fires pushed by howling Santa Ana winds scorched parts of Southern California.
"Fires are breaking out across the so. Cal. Region... Be fire safe. Firefighters are working very hard to minimize damage to property. Evacuations are taking place in many places in Southern California," the Ventura County Fire Department tweeted.
Unpredictable winds and extremely dry brush, victim of little rainfall over the past three months, fueled at least five blazes.
In Los Angeles, at least 500 firefighters watched a fire go from 4,000 acres to 11,000 in a matter of hours.
"We simply don't know what this fire will do," Mayor Eric Garcetti said.
To the west, the biggest blaze had zero containment and it had grown to 50,000 acres -- about 78 square miles -- in just 19 hours.
Some homes were ablaze in the northern part of Ventura, a city of more than 100,000 on the Pacific coast. More than a quarter of the city's residents had been told to get out.
The fire -- the largest of several wind-driven blazes in Southern California -- forced sheriff's deputies to knock on doors to warn residents to evacuate Monday night. About 150 buildings, including homes and an evacuated Ventura hospital, have been destroyed.
On Ventura's northern edge, at least 10 homes and many trees were burning in one neighborhood, sending thick smoke and dangerous embers into the gusty air.
Evacuee Catherine Wastweet, stood on a street Tuesday morning and looked up to the foothills where her neighborhood was aflame.
"We live up there ... but we just don't know whether our house is burned down or not, because we can't even see through all of the smoke," she said.