Heavy rains unleashed destructive rivers of mud and debris in Southern California on Tuesday -- leaving at least 13 people dead, destroying homes and spurring rescues as the flooding forced heavily traveled roads to close.

Santa Barbara County Sheriff Bill Brown said the death toll could rise. Officials said many of the deaths are believed to be in the coastal Montecito area, where mudflows and floodwater have inundated areas downstream from where the Thomas Fire burned thousands of acres last month, reports the CNN.

At least two dozen people were unaccounted for and authorities rescued at least 50 people in the Montecito area. The Santa Barbara Sheriff's Department is working toward determining whether those "missing" were accounted for in other locations or among those who are deceased.

"It looked like a World War I battlefield," Brown said of the destruction. "It was literally a carpet of mud and debris everywhere, with huge boulders, rocks, down trees, power lines, wrecked cars -- lots of obstacles and challenges for rescue personnel to get to homes."

Before the storm hit, Santa Barbara issued mandatory evacuations for more than 6,000 people, including living in those parts of Carpinteria, Montecito and Goleta, located below areas scorched by wildfires, including the Thomas Fire, county spokeswoman Gina DePinto said.

Voluntary evacuation warnings were in effect for another 20,000 people, including others in those same communities, she said.

BDST: 1450 HRS, JAN 10, 2017
AP