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.

Firefighters responded to a brush fire Wednesday north of Los Angeles on a day of red flag warnings for parts of Southern California.

Firefighters fought to maintain the upper hand on a huge and rapidly moving wildfire that swept through rugged mountains north of Los Angeles and resulted in more than 50,000 people being put under evacuation orders or warnings.