A teenager was shot in the head and killed Friday afternoon following an argument in the middle of a Philadelphia street, authorities announced. Police said the incident happened in the Northeast Philadelphia neighborhood of Frankford. The teen was arguing with another person just after 2 p.m. along the 4200 block of Romain Street. The argument escalated and the other person, a male, pulled a gun and fired at least two shots at the teen. One of the bullets hit the victim, also a male, in the head. The alleged shooter then fled the area through an alley, investigators told NBC Philadelphia. He …