Jan. 9 (UPI) -- At least 13 people died as a result of heavy rains that triggered flooding and mudslides in fire-ravaged parts of Southern California.
The rainstorm deteriorated south-facing slopes and flooded a creek leading to the ocean sending mud and massive boulders coursing through Montecito neighborhoods recently ravaged by the Thomas fire, Santa Barbara County Fire Department spokesman Mike Eliason said.
In addition to the 13 deaths at least 25 people were injured. Crews rescued 50 people through the air and dozens more by ground.
"It's going to be worse than anyone imagined for our area," Eliason said. "Following our fire, this is the worst-case scenario."
One person was killed in Los Angeles County when a big rig overturned in the northbound lanes of the 5 Freeway near Los Feliz, Saul Gomez, a public information officer for the California Highway Safety Patrol's Southern Divison, said.
The region is particularly vulnerable after the Thomas Fire last month -- the largest in California history -- burned huge areas of Ventura and Santa Barbara counties.
Charred hillsides left over from the blaze now pose another threat -- flash floods, mudslides and debris flows.
Flooding risks increase after wildfires because the soil is hardened and repels water, potentially increasing stream levels and bringing water to areas where it typically wouldn't go. Vegetation lost in a blaze can also cause mud and debris flows.
Up to 7 inches of rainfall could fall in the foothills and mountains -- all territories that include burn areas.
Santa Barbara County officials evacuated nearly 7,000 residents from foothill communities Sheriff's Office spokeswoman Kelly Hoover said.
"Unfortunately, the bull's-eye of the rainfall is almost right on the Thomas Fire burn area," Kathy Hoxsie a meteorologist with the National Weather Service, said.
The National Weather Service said on Twitter that although the steady rain is ending, the flood threat remains.
Monday night, there were reports of numerous mudslides, downed trees and road closures, including the 101 Freeway in Ventura. Mudflows also knocked three homes from their foundations and left fire personnel struggling to rescue people trapped in their vehicles and homes.
Many areas remained inaccessible as the search for survivors continued Tuesday, officials had no estimate for how many people were trapped or homes were damaged.