A 39-year-old man was killed on Thursday night when a teen opened fire on a crowded B15 bus in Bedford-Stuyvesant. The Daily News reports that the shooter is a 14-year-old boy, who was sitting in the back of the bus with friends. At about 6:20 p.m. an apparent rival boarded at Marcus Garvey Boulevard and Lafayette Avenue. “One kid pulls out a gun and he lets off a couple of rounds,” a source said. “He’s running out of the bus, still letting rounds go, and this poor guy gets shot in back of the head. He wasn’t the intended victim.” The victim was pronounced dead at Woodhull Hospital. Police have not released any details about the shooter, but say they’ve taken a man into custody and seized a handgun from him.