Highway 5 north of Los Angeles has been closed and a "on-the-spot shelter" order has been issued for residents of the town of Castaic after a gas pipeline burst on the afternoon of December 27 (local time).
Los Angeles County Fire Department officials said they received reports of an explosion in the area near Ridge Route Road and Pine Crest Place around 4:20 PM, followed by reports of a strong gas smell.
Highway 5 is a vital traffic route connecting Southern California with the rest of the state. This route runs north, passing through Oregon and Washington before reaching Canada.
The cause of the pipeline - identified as a "gas pipeline" - breaking is still unclear. However, police from the Los Angeles County Sheriff's Office announced that the incident may have been caused by mudslides.
The Los Angeles Fire Department said that emergency response forces are waiting for employees of the SoCal Gas gas distribution company to lock the pipeline valve so that the investigation can begin.
No evacuation order has been issued yet, but firefighters said residents living within a radius of about 1.6km around the pipeline were asked to take shelter on the spot.
California Highway Patrol (CHP) issued a warning immediately after 5 pm, closing both north and south lanes of Highway 5 north of Lake Hughes Road.
East and west lanes of the SR-318 and SR-126 routes are also closed to serve traffic diversion. There is no information about the time to remove the warning. Images from helicopters of local media show queues of traffic jams stretching many kilometers from the warning area.
No injuries have been recorded so far.
Fire and explosives investigators from the Los Angeles County Sheriff's Office, along with a team handling dangerous materials, were dispatched to the scene.
