TUCSON - Tucson Fire units are on the scene of a fire at an apartment on Fairview Ave. north of Prince Rd. Witnesses reported seeing smoke coming from a back window of an upstairs unit. No word on injuries or a cause at this time. A News4 Tucson crew is on the way to the scene. Tune in to News4 Tucson Saturday at 5:30 p.m. for complete details.