A new fire broke out Wednesday night along the 405 Freeway in the Sepulveda Pass. The fire was burning on the east side of the 405 near the Sepulveda Fire Road. Winds were at about 5 mph, according to the Los Angeles Fire Department.

The Hughes Fire in northern LA County grew with alarming speed on a day of red flag warnings in Southern California.

Watch Duty, a nonprofit that tracks wildfires, said that as of 11:26 p.m. the fire was estimated to be 10 acres, burning in heavy brush east of the freeway in the Sepulveda Pass. By about 12:23 it had grown to 20 acres, though fire crews were making good progress on the blaze, Watch Duty reported.

The Hughes fire has prompted mandatory evacuations in Castaic, California, as the fire has a "rapid rate of spread" Cal Fire said.

LET’S GO TO L.A. COUNTY NOW, WHERE A FIRE HAS FORCED THOUSANDS OF PEOPLE TO EVACUATE AS CREWS HAVE RUSHED IN TO TRY TO PROTECT HOMES. THE FIRE STARTED YESTERDAY JUST EAST OF CASTAIC LAKE, AND THE WIND PUSHED THE FIRE WEST TOWARD HOMES AND BUSINESSES.