Authorities say a semi-truck traveling northbound skidded across lanes and crashed through the center divider into southbound lanes at Camino de Estrella at about 1 p.m. At least six cars were hit.
Eight people, including a 1-year-old and a 3-year-old, were rushed to area hospitals with moderate injuries. One other person was hospitalized with minor injuries.
According to the California Highway Patrol, the accident scene spread out over 300 feet. The cause of the accident remains under investigation.
Southbound lanes were shut down due to the crash, backing up traffic for miles. All lanes have since reopened.