One of the victims, a child, was critically injured in the crash, according to Los Angeles Fired Dept. Spokesman Brian Humphrey.
According to a witness, a black truck and white Infiniti vehicle were racing at high speed when the car overturned.
A motorcycle was reportedly involved in the multi-vehicle accident.
The number one and two lanes were re-opened to southbound traffic. The California Highway Patrol was on scene to direct traffic.