A Saturday morning fire destroyed a multi-tenant residence at 3420 N. 21st St. and displaced three residents. One firefighter experienced medical difficulties and had to exit the structure, according to a release from Battalion Chief Scott Gordon with the Superior Fire Department. The firefighter was taken by ambulance to St. Luke’s Hospital, where he was treated and released. No other injuries were reported. All three fire trucks and 12 firefighters responded to the structure fire at 5:33 a.m. Saturday. The multi-story, multi-family building had heavy smoke showing from three sides,. All three tenants were out of the building.