A man on the second floor of an apartment building was struck by stray gunfire late Monday in Morgan Park on the Far South Side. About 11:50 p.m., a 23-year-old man was walking into a residence in the 1300 block of West 109th Place when someone in a vehicle approached and opened fire in his direction, Chicago police said. The bullets missed him but traveled to the second floor of an apartment building, where they struck a 49-year-old man in his abdomen, police said. He was taken to Christ Medical Center where he was in critical condition, officials said. The shooter fled and wasn't in custody. Area 2 detectives are investigating.