A man was shot in Back of the Yards on Sunday night, Chicago police said.The man, 23, walked into a fast food restaurant in the 1400 block of West 47th Street about 8:53 p.m. with a gunshot wound to his back, police said. He was taken to University of Chicago Medical Center in critical condition.Police said the shooting occurred in the 4800 block of South Ada Street, though the circumstances of the shooting weren't available.No one is in custody.