A vacant three-story home went up in flames Thursday morning in west St. Louis. That fire is the second in two days believed to be set by the homeless. Temperatures dipped to near freezing Thursday morning and will do so again early Friday. St. Louis firefighters are concerned these fires could become more numerous. Before dawn, fire could be seen pouring out of the windows of the home on Cabanne Avenue, near Union, in the Visitation Park neighborhood. Firefighters conducted a search but had to evacuate due to the danger of the flames. Three people were able to escape the burning building and were taken to the hospital with non-life-threatening burn injuries.