Dispatchers started receiving calls at 2:58 a.m. about gunfire in the 1000 block of W. Sixth Street.
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At about the same time, dispatchers with the Contra Costa County Sheriff's Office told police that a victim from a shooting in Antioch was at Century Plaza in Pittsburg, according to Antioch police.
According to a police investigation, shots were first fired at the Antioch Marina when a fight broke out among a group of people, police said.
The altercation continued when the people left the marina in their vehicles and fired more shots in the 1000 block of W. Sixth Street, according to police. Someone drove the injured girl to Century Plaza where a person called 911, police said. The girl was taken to a hospital.