CAJON PASS, CALIFORNIA — A SigAlert was issued Monday morning after a semi-truck jackknifed and overturned on southbound Interstate 15 in the Cajon Pass, blocking multiple lanes and triggering major delays through the pass following a crash involving at least three vehicles.

^{Photo credit: Asia Loera}

The incident was reported at approximately 10:05 a.m. on January 5, 2026, and included a semi-truck and a gray Honda Accord, with a third vehicle believed to also be involved. According to the California Highway Patrol incident log, a reporting party said another vehicle cut him off, causing him to collide with the semi.

A scene photo showed the semi jackknifed with its trailer overturned across all southbound lanes, while the cab remained upright. A forklift was also visible nearby in the center divider, though it was unclear whether it was being transported by the semi.

^{Photo credit: Asia Loera}

The gray Honda Accord suffered noticeable damage to the front driver’s side, including a bent wheel well and a partially detached bumper.

CHP issued the SigAlert at 10:22 a.m., confirming all lanes were initially blocked. By 11:11 a.m., only the #1 lane was open, while lanes #2, #3, and #4 remained coned off from the switchbacks to the crash scene.

^{Photo credit: Asia Loera}

As the cleanup and recovery continued, southbound I-15 traffic backed up into Hesperia by Joshua Street late Monday morning. Tow resources, including a rotator from G&M Towing, were reported delayed due to the heavy congestion approaching the incident area.

This remains a developing situation, and additional updates are expected as more information is released.

📸 Image(s) used under fair use for news reporting.