A 16-year-old who police say punched a 60-year-old man in the face on a SEPTA subway platform, breaking his jaw, turned himself Thursday afternoon, SEPTA officials said.

The boy, whose name was not released, will be charged with aggravated assault, simple assault, and reckless endangerment of another person. He surrendered with his attorney at Philadelphia's Ninth Police District.

Police say the boy got into an argument with the man on a Market-Frankford Line train traveling westbound March 30. The argument continued for several stops, they said, until the teenager and his friends - as well as the man - exited on the 15th Street platform.

That's when, police said, the boy punched the man in the jaw, knocking him unconscious. The teenagers fled, and other riders alerted a SEPTA cashier, who called police. The man was treated at Hahnemann University Hospital. - Aubrey Whelan