Sgt. Dirk Dewachter tells City News Service that the car may have been speeding when it wrapped around a light pole Wednesday night.
Dewachter says the boy was in a safety seat but he ended up hanging out of the car and was pronounced dead at a hospital.
The injured driver, an Inglewood man in his 20s, was arrested and taken to a hospital.
Dewachter says the driver had a relationship with the boy's mother but he wasn't the father.
Dewachter says witnesses said the car may have been racing another vehicle but that's not confirmed.