Mudslides and Flash Flooding Damage Homes and Roads in Southern California

Heavy mudslides and flash flooding struck Southern California on Thursday, September 18, 2025, following thunderstorms fueled by remnants of former Eastern Pacific Tropical Storm Mario. The storms caused extensive damage across San Bernardino County and surrounding areas.

Areas Hardest Hit

The mountain communities of Oak Glen, Forest Falls, and Potato Canyon were particularly affected. Mud and debris flows damaged multiple homes and buried roads, approximately 80 miles east of Los Angeles, according to the San Bernardino County Fire Department.

Vehicles Stranded and Rescued

Ten people traveling in at least six vehicles were trapped for roughly 10 hours on Highway 38 after debris blocked the roadway in both directions. All were safely rescued, and no injuries were reported. The highway remained closed as of Friday morning while assessment teams continued searching for others in need of assistance.

Fatality in Barstow

In Barstow, a 2-year-old boy was found dead after being separated from his father when their vehicle was swept away by floodwaters on Thursday evening. The child’s body was recovered at approximately 2:44 p.m. Friday in the San Bernardino County Flood Control channel, south of the Mojave River.

Shelter Advisories and Ongoing Assessment

Residents in Oak Glen were instructed to shelter in place. Damage assessment teams are working to evaluate the number of buildings affected and the extent of property loss. Authorities have noted that previous mudslides in Oak Glen and Forest Falls in 2022 were linked to the 2020 El Dorado wildfire burn scar, which increases flash flooding risks in steep terrain.

Rainfall and Storm Details

Some areas reported 1.77 inches of rain in a single hour, while Big Bear Lake averages less than half an inch in September. The combination of residual tropical moisture from Mario and warm afternoon sunshine produced thunderstorms that intensified rainfall across the mountains and deserts.

Broader Impacts

Flash flooding also affected roads in southeast California deserts. Death Valley National Park was under a flash flood warning early Friday, with water and debris covering State Route 190 near Furnace Creek. The flash flood threat ended in Southern California on Friday, though lingering moisture may trigger localized flooding in the Sierra Nevada and other Desert Southwest areas.