All four G.I. fire stations were called out to the G.I. Somali Coffee Shop at 1600 South Eddy Street around 3:00 p.m.
Fire officials said insulation over a faulty fan motor was causing smoke to pour into the business.
"Had the residents not called us and had that smoldering turned into an actual fire, because this structure is old and the roof is made out of wood, we could have had a very severe fire here today," said GIFD Shift Commander Scott Kuehl.
Kuehl said around eight people were in the business when the 911 call was made.
He said as soon as the fan is fixed, the business can re-open.