Janesville firefighters are investigating a weekend fire in an apartment building on South High Street. Fire Captain John McManus says all the occupants had escaped the burning two story, four unit building, when they arrived on scene a little before noon Sunday. McManus says both smoke and fire damaged the basement, first and second floors of the building. Damage is estimated around $100 thousand for both the structure and contents. Five occupants were displaced. One firefighter needed stitches for cut on his arm. The cause is under investigation.