Summary: A large group of approximately 15 youths reportedly robbed and assaulted a male at the intersection of Lake Street and Wabash Avenue in Chicago, Illinois. The incident involved the theft of a phone, physical battery, and citizens intervening to detain one of the offenders. Police responded to the scene, made contact with the victim, and coordinated with other units to transport the victim and offenders. The event also involved medical response and the completion of official paperwork.