Fire investigators are calling an early morning fire arson. The Evansville fire departments Dan Grimm tells us they found combustibles inside the vacant building, along with straw. Firefighters were called out to Fulton and Fountain around three oclock. Thats the site of the old Kirbys Thrift Shop. When crews got there, the building was fully engulfed. Firefighters werent the only ones working to put out the fire safely. Vectren crews came to shut off power. Investigators determined the fire was set in the back of the building. There arent any suspects yet.