A 21-year-old man killed early Thursday in the Riverdale neighborhood on the Far South Side. Jadon Johnson was shot while sitting in a parked vehicle in the 13300 block of South Indiana about 12:10 a.m., police and the Cook County medical examiner’s office said. Johnson was driven by a relative to Roseland Community Hospital, where he was pronounced dead at 12:32 a.m., authorities said.