Land movement was "most likely cause" of Castaic gas pipeline break, SoCalGas says

The natural gas pipeline that ruptured on Saturday afternoon, temporarily closing the 5 Freeway and forcing thousands of people to shelter in place in Castaic, was likely caused by land movement, according to SoCalGas. 

It happened at around 4:20 p.m. on Saturday near Ridge Route Road and Pine Crest Place, according to Los Angeles County Fire Department crews. They were called to the location after receiving reports of an explosion followed by a strong gas smell in the area. 

Aerial footage showed natural gas rushing out of the pipe, kicking up clouds of dirt and sending them across all lanes of the busy I-5 in the midst of holiday travel traffic. All lanes were closed for several hours as SoCalGas officials worked to mitigate the leak. 

On Monday, they said that their investigation into the break was ongoing, but that "significant land movement has been observed at the site of the break, and a preliminary inspection of the area by a geologist has determined this was the most likely cause of the pipeline break."

At the time of the break on Saturday, they said that the 600 psi 34-inch main gas line would still leak some residual gas, leaving a lingering natural gas smell over much of the San Fernando and Santa Clarita valleys. 

SoCalGas crews began to assess the broken line on Sunday, stating that repairs would get underway as quickly as possible. They said that five "non-residential natural gas customers" had their service affected by the break, but that the pipeline is mainly used for transportation. 

Despite reports of an explosion, accompanied by the loud rushing sound of the gas coming out of the pipeline, they said there was no evidence that there was an ignition or explosion on Saturday. 

Though there were never any evacuations ordered, 19,200 residents were asked to shelter in place and close their doors and windows as the incident continued. The 5 Freeway was closed in both directions until around 9 p.m., nearly five hours after it was first shut down by the California Highway Patrol. No injuries were reported from the incident.