Southern California experienced devastating flash floods and mudslides caused by the remnants of Tropical Storm Mario on the 18th of September, 2025, leading to several water rescues and emergency responses. The Oak Glen, Forest Falls, and Potato Canyon regions of San Bernardino County were the worst hit as the mud and silt covered homes and buried roads. There they were trapped on Highway 38, where 10 people were rescued after 10 hours, and in relation to this, one 2 years 2-year-old boy was lost in another flood.
Tropical Storm Mario remnants trigger widespread emergency response
Remnants of Tropical Storm Mario brought widespread rainfall to California and the Desert Southwest on September 17 and 18, 2025, prompting water rescues, triggering mudslides, and flash flooding across the region, according to Watchers News. Moisture from the remnants of Tropical Storm Mario reached California and parts of the Desert Southwest on September 17, producing heavy rainfall that led to flash flooding, mudslides, and debris flows.
The National Weather Service (NWS) placedย more than 7 million peopleย under flood watches across Southern California and neighboring states, citing particular concern for mountainous regions and burn-scarred slopes vulnerable to debris flows. In California’s San Bernardino County, flooding on September 18 prompted water rescues, including one in the area of Boulder Avenue and Baseline Street in the City of Highland.
Ten people trapped for hours on Highway 38
Deep mudslides and flash flooding hit Southern California on Thursday after drenching thunderstorms fed by the moisture of former Eastern Pacific Tropical Storm Mario spread over the region, according to CNN. 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 need assistance.
A two-year-old boy dies in the Barstow flooding
Just north, in the city of Barstow, a 2-year-old boy was found dead after being separated from his father when their vehicle was swept away by floodwaters Thursday evening, the city of Barstow wrote in a Friday statement. The boy’s body was found at approximately 2:44 p.m. Friday in the San Bernardino County Flood Control channel, south of the Mojave River.
“We ask that the privacy of the grieving family be respected as they navigate this devastating loss,” the statement read. 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.
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.
Although the overall outcome of the immediate rescue was successful in the majority of the cases, the loss of the small child shows the potential for lethality of flash floods in the desert areas. With the ever-strengthening of climate patterns, which enhance storm systems, communities in fire-prone regions would be required to strengthen their preparedness to face the risks of debris flows and flooding when there is a wildfire in the area.