According to the California Highway Patrol, officers received a call around 4:30 p.m. about a black Toyota SUV that had crashed within the center median of the 15 Freeway, just south of Halloran Summit Road near milepost marker 154.
The SUV was heading northbound on the 15 when the driver somehow veered to the left toward the center median, according to CHP.
"The SUV crashed into the guardrail and continued in a northeast direction and struck a concrete embankment within the Kali Ditch, near mile post marker 15 SBD 154," said CHP in a statement released Sunday.
All three passengers inside the SUV died at the scene. In addition to the child, a 43-year-old woman and a 56-year-old man were also killed.
The victims have not been identified.
It's unknown if alcohol and/or drugs played a role in the crash.
The collision remains under investigation. Anyone with information is urged to contact Officer L. Roberson at 760-255-5900.