Unplanned fire on the property was observed at 8:30pm. Fire dpt was dispatched at 8:30pm. Site personnel confirmed dry tower area/belting was on fire at 9:15pm. Fire was extinguished by local fire dpt around 9:30pm. Hot work activities that occurred on the dry tower area around 7:30pm are believed to be a contributing factor. Last employee left the site around 7:53pm.