A serious crash early Wednesday morning forced the closure of multiple southbound lanes on Interstate 5 near Camp Pendleton, causing heavy traffic delays for commuters traveling through North County San Diego.

According to the California Highway Patrol (CHP), the incident happened around 1:45 a.m. near the Aliso Creek Rest Area.

Authorities said the semi-truck driver veered onto the right shoulder for reasons still under investigation, crossed several lanes of traffic, and eventually slammed into a guardrail, causing the truck to overturn on the freeway.

Following the initial crash, two additional vehicles collided with the overturned big rig, further impacting traffic conditions in the area.

The semi-truck driver suffered major, but non-life-threatening injuries and was airlifted to a local hospital for treatment. Meanwhile, the driver of a Honda CR-V sustained minor injuries and was also taken to a hospital for evaluation.

Emergency crews remained on scene for several hours clearing debris and cargo scattered across the freeway.

Authorities said the overturned truck appears to belong to FedEx.

A driver who spoke with Baja News reported delays of up to two hours, while both northbound and southbound lanes were partially affected at different points during the incident.