The incident was reported to authorities by a passerby around 7:20 a.m. near Mt. Emma Road and Angeles Forest Highway.
Authorities said a 44-year-old and a 10-year-old were trapped inside the vehicle. A third person was said to be on the roadway.
Fire crews were able to rescue the two victims from the car.
Two patients were airlifted to a hospital, and one was transported by a ground ambulance. Their conditions were not immediately known.