Several homes and cars were swept away in the mudslides and flooding triggered by the torrential rainstorm.
Local media quoted Santa Barbara County Sheriff Bill Brown as saying at a press conference, "We realize that this is going to be a long and difficult journey for all of us and our community."
"Death toll is likely to rise," said Brown on Tuesday, reported CNN.
"It looked like a World War I battlefield," said Brown on Tuesday and added, "While we hope it will not, we expect that this number will increase as we continue to look for people who are still missing and unaccounted for."
Rescue operations have been carried out throughout the day in Montecito, an enclave which houses celebrities like Oprah Winfrey, Ellen DeGeneres and several other celebrities.
Oprah Winfrey has a property in Montecito that is reportedly worth nearly $90m.
According to the National Weather Service, more than 5.5 inches of rain had fallen in parts of Ventura County over two days.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)