Search and rescue efforts have been slow as crews have had to make their way through waist-deep mud, fallen trees, boulders and other debris.
"We heard this monstrous sound that was like a freight train", said Carrie Tighe. That's because burned soil can act as a water repellent like pavement, so rainfall that would normally be absorbed in the ground runs off rapidly after a wildfire. As much as 13 centimeters of rain fell in some places.
As the floodwater gushes downhill through burned areas, it can create major erosion and pick up vast amounts of ash, mud, rocks, sand, silt and scorched vegetation like trees and shrubs. With the wildfires leaving behind a waxy layer of debris that made it hard for water to infiltrate the ground, the downpour caused flash floods in the fire-scarred Santa Ynez Mountains. "It was a carpet of mud and debris".
The grim discovery came around noon on a day in which searchers were going through damaged and destroyed homes, sometimes for a second time.
In Montecito, a 14-year-old girl was rescued after several hours from the rubble of a home destroyed by the heavy rains.
It could include everything from urgent, active missing-persons cases being worked by detectives to calls received from acquaintances saying they hadn't been able to reach someone they believe was in Montecito on Tuesday morning when mudslides swept through town and killed 17 people.
People in Montecito avoided the ravages of the biggest wildfire in California history last month.
Santa Barbara County Fire Department spokesman Mike Eliason said: "We've got a window that's closing but we're still very optimistic we've got some time".
The rain was lighter in the desert than in coastal areas, but the downpour shattered a January 9 Palm Springs record of 1.13 inches set in 1980, according to the weather service.
The mud and debris overwhelmed many homes and wiped some of them out.
Oprah Winfrey has shared intimate footage of the devastation caused by a Californian mudslide. Thousands of people in Southern California were under evacuation orders, including Santa Barbara, Ventura and Los Angeles counties.
A devastating mudslide has killed at least 15 people in Montecito, Santa Barbara, but why do mudslides happen and what made this one so unsafe?