LOS ANGELES — Four wildfires roared through Southern California on Tuesday, forcing the evacuation of tens of thousands of people and destroying hundreds of homes and other buildings in the latest chapter of what has been one of the state’s worst fire seasons.

The first fire, in Ventura County, started Monday evening and was still “out of control” on Tuesday night, the authorities said. Named the Thomas Fire, it began north of Santa Paula, Calif., and spread rapidly overnight on Monday to envelop at least 50,000 acres, destroying hundreds of structures and prompting 27,000 people to evacuate, including some from the city of Ventura.

Three more fires began on Tuesday. One in Los Angeles County quickly grew to encompass more than 11,000 acres and destroyed more than 30 structures. Another, in San Bernardino County, injured three people as it burned 100 acres of vegetation. And a fourth, near Santa Clarita, tore through at least 5,000 acres, forcing the evacuation of a trailer park and several schools.