Significant rainfall in Oak Glen Thursday triggered a mudslide that covered roads and trapped multiple people inside their vehicles, according to Cal Fire.
Search and rescue teams were activated in San Bernardino County to help those trapped get to safety. A California Highway Patrol officer was among those trapped, Cal Fire said.
Drones and helicopters were being used during search operations.
Oak Glen Road at Glen Road and Fawn Way was closed due to the debris flow. State Route 38 at Valley of the Falls Drive was also completely shut down by authorities.
Several residents in the Oak Glen area were instructed to shelter in place, Cal Fire said.
Cellphone video shared with NBC4 showed multiple vehicles trapped in the mud as well as streets flooded with debris.
No injuries were reported.
SR-38 is completely shut down due to heavy flooding and mudslides. There is an unknown ETA for the highway to open. We urge all drivers to use alternate routes and plan your travels accordingly.
Stay tuned for further updates as we monitor the situation. Stay safe! pic.twitter.com/b9MKa1WPXq
— CHP Arrowhead (@CHPArrowhead) September 18, 2025
Remnant moisture from Tropical Storm Mario is moving through Southern California. Showers and thunderstorms were in the forecast Thursday morning, bringing the chance of flash flooding in Los Angeles County.
A flood watch is in effect for most of the mountains from San Luis Obispo to Los Angeles County beginning Thursday morning, according to the National Weather Service. Burn scar areas in Altadena and Pacific Palisades are part of the flood watch advisory.