In early January 2018, a series of mudflows occurred in Southern California, particularly affecting Ventura and Santa Barbara Counties. The 2017 California wildfire season was at the time the most destructive in California’s history, with approximately 1.3 million acres burned. Of these, 281,893 acres were burned during the Thomas Fire, the largest in the state’s history, which devastated large amounts of vegetation whose roots had helped stabilize topsoil in hillsides and other vulnerable areas. In the meanwhile, a strong low-pressure system and cold front developed off the coast and moved onto the mainland, bringing heavy rain and prompting mandatory evacuations over potential mudslides in areas affected by wildfires. The storm intensified on the following days, with at least four inches of rain falling over the two-day period, causing mud and boulders from the upper mountains to flow down creeks and valleys into surrounding towns. The conflagrations devastated steep slopes, which caused loss of vegetation and destabilization of the soil and greatly facilitated subsequent mudflows and geo-hazard exposition.