The 14-year-old victim was on her way home from a birthday party at a neighborhood club when someone on the sidewalk opened fire on the bus at a stop in the Jamaica section of the borough.
The girl, whose name was not released, was struck in the head by at least one of the 10 rounds fired and was pronounced dead at a hospital.
The motive for the shooting was not known, but party guests said there had been no trouble at the party that might explain the violence.
"The cops were just questioning me to see if it was a private event, who was here, and when they left," a woman outside the bar told the New York Post. "There was no altercation here. It's not like anything spilled out from here."