It happened on Interstate 5 near Highway 198 just before 8 a.m. Saturday.
Authorities say the driver of a Chevy Surburban swerved to avoid a big rig and lost control.
The SUV crossed the median and crashed into a Toyota 4-Runner.
The 38-year-old driver of the Chevy died at the scene, along with a 44-year-old and 7-year-old passenger.
Two teenagers and ten year old in the vehicle were injured.
All five people in the 4-Runner were also hurt, including three children.
Investigators are now searching for the big rig driver, who left the scene.
