"The teen shot himself while he was playing a game of Russian Roulette,'' sheriff's Detective Scott Holund told reporters at the scene.
His name has not yet been released by authorities.
Detectives said the unidentified youth, who was living with his older brother and his sister-in-law, got his hands on a .38 Special Revolver and announced he was going to play a game of Russian Roulette, Deputy Juanita Navarro-Suarez said.
Two other minor children who were present in the teen's bedroom pleaded with him not to do it, but the 17-year-old pulled the trigger and shot himself once in the head, Navarro-Suarez said.
The gun was recovered at the scene. It's unclear, so far, who owns the weapon. Navarro-Suarez said the teen's death has now been ruled "accidental."
The shooting in the 900 block of West Carson Street was reported just after midnight, said Deputy Kelvin Moody of the Sheriff's Information Bureau.
The area where the shooting occurred is wedged between Carson to the east and the Harbor Gateway area of Los Angeles to the west.
The victim was transported to a hospital across the street from his apartment building where he was pronounced dead, Moody said.