Commuters ducked for their lives as the chaos unfolded just after 6 p.m.
The gunfire during the evening commute sent passengers ducking to the floor of the train before it pulled into the 80th Street station.
A witness on the train heard the shots and saw how desperate everyone was to get out once the doors opened.
"It was pandemonium, everybody just took off running, man. Including the two guys, the teenagers that were fighting," said eyewitness Junior White.
White was two subway cars away and says his heart stopped when heard the sound.
"We all jumped onto the floor and stayed below, and the doorman opened the doors up and some people ran out, but I stayed below," White said. "Some people saw the guys who did it and identified to police how they looked."
Police say the 15-year-old victim was shot at least one time in the chest. Officers took him to Jamaica Hospital in an NYPD vehicle. He's in stable condition.
It didn't appear that anyone else was shot or hurt in the scramble.
NYPD officials say police took two persons of interest, both teens, into custody, but have since been released. Police are still looking for their suspects.
Detectives are trying to determine what the fight was about and whether the victim knew the shooter.
Queens District Attorney Melinda Katz stopped by the scene as police collected evidence, including any video at the 80th Street station and on the stopped train.
"Any time there is a shooting on a train, it is a tragedy for the city of New York, and so we hope to get many more of these weapons off the street and out of the hands of our young people," Katz said.
Police are still looking for the weapon that someone brought to this fight and dangerously decided to use on a moving train.
Meanwhile, A trains are severely disrupted between Manhattan and Queens as the NYPD conducts an investigation at 80th Street.
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