Firefighters have so far rescued 50 people trapped in mud, and emergency responders plan to continue search efforts through the night.
In Montecito, mudflow and debris wiped six homes away from their foundations. Recent wildfires devastated the coastal community, leaving burned areas vulnerable to the dangers of heavy rains.
By early Tuesday afternoon, more than 4 inches of rain had fallen in parts of Santa Barbara County, and more than 5.5 inches in parts of Ventura County. The rain is expected to clear all of the Los Angeles area by late Tuesday.