A fast-moving wildfire exploded to roughly 10,200 acres near the Los Angeles County community of Castaic Wednesday morning, prompting mandatory evacuation orders and road closures, authorities said.

Thousands of Southern California residents were under evacuation orders Wednesday as fire crews battled the out-of-control Hughes Fire near the town of Castaic, a suburb in the foothills and mountains of northern Los Angeles County.

Lilac Fire initially started today at 1:19 a.m. in San Diego County. It has burned 85 acres after being active for 19 hours. A crew of 66 firefighters succeeded in containing 50% of the fire as of Tuesday evening. Investigations into its cause are still ongoing.

A new fast-moving wildfire has erupted in Los Angeles County, triggering evacuations in a region already reeling from the most destructive fires in its history. The Hughes fire ignited north of the city on Wednesday afternoon, near Castaic Lake in a mountainous area that borders several residential areas and schools.