A major natural gas pipeline exploded near Castaic, northern Los Angeles County, on Saturday afternoon. The blast happened around 4:20 pm near Interstate 5, a key highway connecting Southern and Northern California. The damaged pipeline was a 34-inch transmission line just east of the freeway. Multiple emergency calls reported a gas leak. Los Angeles County Fire Department spokeswoman Capt. Brian Kight said, "there were no reports of any explosions from the leak and no reported injuries," according to the Los Angeles Times. Social media videos showed orange flames and smoke from a hillside, which partly collapsed with clouds of debris. Many people heard loud booms. NBC 7 San Diego said residents in the Santa Clarita Valley felt their homes shake. One witness described a "strong sulfur smell and a loud noise resembling a jet engine," the report added. At Fire Station 149, about a mile from the site, Kight said he could smell gas from "20 minutes out." The Los Angeles City Fire Department received reports of a strong rotten egg smell from as far away as north San Fernando Valley. The California Highway Patrol closed all lanes of Interstate 5 at 5:12 pm. Northbound drivers were redirected to State Route 126 and southbound to State Route 138. Traffic slowed to a near stop for miles, stranding drivers for hours. A shelter-in-place order was issued at 5:40 pm for much of Castaic, advising people to keep doors and windows closed and turn off HVAC systems. By 6 pm, the gas company shut off both sides of the broken pipeline. Firefighters and hazardous materials teams kept watch on a small residual leak. The CHP reopened Interstate 5 shortly before 9 pm. The cause of the rupture is still unknown. Los Angeles County Sheriff’s deputies told CBS Los Angeles it may have been caused by a "mudslide." Officials continue to investigate. More updates are expected soon.