Deep mudslides and flash flooding hit Southern California Thursday after drenching thunderstorms fed by the moisture of former Eastern Pacific Tropical Storm Mario spread over the region.
The Oak Glen, Forest Falls and Potato Canyon areas of San Bernardino County were particularly hard hit. Mud and debris flows impacted multiple homes and covered roads across the area, about 80 miles east of Los Angeles, San Bernardino County Fire said.
Ten people traveling in at least six vehicles were rescued after being stuck for around 10 hours on Highway 38 as debris covered the road in both directions, the Associated Press reported. No one was injured and the road remained closed as of Friday morning.
No other motorists were known to be stranded as of late Friday morning, according to San Bernardino County Fire, but “assessment teams and field crews are continuing to search the area to ensure no other parties are in need of assistance.”
Just north, in the city of Barstow, a search was underway for a 2-year-old boy who was swept away by floodwaters Thursday evening, according to local police.
People in numerous homes were told to shelter in place in the Oak Glen area, but no injuries had been reported, according to the Cal Fire San Bernardino Unit Public Information Office.
County damage assessment teams will work Friday to evaluate the number of buildings impacted and the extent of property loss from the mudslides, according to the county fire department.
Oak Glen and Forest Falls were the site of another mudslide that swept into homes and roads in September 2022. Cal Fire has said both mudslides are linked to the 2020 El Dorado wildfire burn scar, CNN affiliate
ABC7 in Los Angeles reported. That fire was sparked by a pyrotechnic device at a gender reveal party.
Rain tends to run off rapidly on fire scarred land — especially in steep terrain — increasing flash flooding risks even when a storm’s rainfall isn’t extreme. Combined with thunderstorms packing intense rainfall rates, it was the perfect recipe for mudslides and flooding Thursday.
One location near Forest Falls reported 1.77 inches of rain in a single hour. Big Bear Lake in the mountains north of the community averages less than a half-inch of rain in September.
September is still in the tail end of the dry season in much of Southern California, but a boost of tropical moisture from former Tropical Storm Mario combined with energy from warm afternoon sunshine to generate thunderstorms over the state’s mountains and deserts Thursday afternoon.