According to the Long Beach Police Department, the girl died Saturday after spending days in the hospital in critical condition.
The shooting happened around 8:30 p.m. Tuesday night near 11th Street and Lewis Avenue. When officers arrived, they found the girl suffering from a gunshot wound to her upper body.
A preliminary investigation revealed the teen was walking down the street when she was approached by a suspect or suspects and was shot, police said.
A man who did not want to be identified told Eyewitness News that the girl was his cousin and said she was "fighting for her life."
The case is now being investigated as a homicide and no arrests have been made.
Anyone with information was asked to call detectives Ethan Shear or Chasen Contreras at 562-570-7244.
Meanwhile, a GoFundMe has been created to help the family.