A rupture of a high-pressure 34-inch natural gas transmission line late Saturday afternoon forced the temporary closure of Interstate 5 north of Los Angeles for several hours and led to a shelter-in-place order for thousands of residents in Castaic. Capt. Brian Knight, a spokesman for L.A. County Fire, told ABC News that a loud blast was reported around 4:20 p.m. local time. Knight said there were no reports of any injuries. BREAKING: A massive 36-inch underground natural gas pipeline rupture sent high-pressure gas spewing into the air across the Santa Clarita Valley moments ago, prompting emergency evacuations and shelter-in-place orders in the Castaic area. The rupture was reported shortly before… pic.twitter.com/37GsIfx9fI — Austin Dave (@AustinDave_) December 28, 2025 WATCH: Loud booms heard as major gas line explosion triggers shelter-in-place in Castaic, California https://t.co/7pHnuSxNVu pic.twitter.com/0Xf8jcviAe — Rapid Report (@RapidReport2025) December 28, 2025 The damaged line was identified as a 34-inch, 600-psi transmission pipeline that released NatGas into the air and led to a shelter-in-place order for 14,900 people across the Charley Canyon, Hillcrest, and Wayside communities. …