Natural Gas Pipeline Rupture in Castaic Disrupts I-5 Freeway, Prompts Shelter-in-Place Order

Castaic, California - December 27, 2025A major natural gas pipeline ruptured Saturday afternoon in Castaic, north of Los Angeles, forcing the closure of all lanes on Interstate 5 in both directions and triggering a shelter-in-place order for nearby residents.

The incident occurred around 4:20 p.m. near Ridge Route Road and Pine Crest Place, just east of the southbound lanes of the I-5 freeway. Los Angeles County Fire Department officials reported that the rupture involved a high-pressure transmission line operated by SoCalGas, described in reports as a 34- to 36-inch main line.

Witnesses and residents described hearing a loud explosion followed by a persistent roaring sound likened to a "jet engine." A large plume of natural gas was visible billowing into the air, creating a significant white cloud over the area.

Early reports from the scene indicated a landslide in the hilly terrain may have contributed to or resulted from the rupture, though authorities have not confirmed the exact cause. The incident is under investigation.In response, the California Highway Patrol issued a SigAlert and closed all northbound and southbound lanes of the I-5, diverting traffic to alternate routes such as State Route 126 and State Route 138.

The closure caused significant traffic backups in the area.At approximately 5:40 p.m., a shelter-in-place order was issued for much of Castaic, including neighborhoods near Northlake Hills Elementary School. Residents within about a one-mile radius were advised to remain indoors, close doors, windows, and vents, and turn off HVAC systems to avoid exposure to the gas.

SoCalGas crews worked alongside emergency responders to isolate the damaged section of the pipeline. By around 7:30 p.m., officials reported that the flow of gas had been stopped, though residual gas continued to vent safely. A SoCalGas spokesperson stated that once the remaining gas is vented, crews will assess the damage and begin repairs.

No injuries were reported, and there were no indications of fire or explosion beyond the initial rupture. The shelter-in-place order was expected to be lifted once air quality was deemed safe.

The I-5 freeway, a critical north-south corridor in California, remained closed into the evening as cleanup and safety checks continued. Motorists were urged to avoid the area and check for updates from the CHP.