Sioux Falls, SD (KELO-AM) Sioux Falls Fire crews were called to a blaze at the Natural Food Co-Op early Sunday morning. Appproixmately 3:15 this morning, fire rescue was dispatched to the fire, reported by a passer-by. A blaze near the entryway was extinguished in 5 minutes time, but not before extensive smoke damage affected the building. Investigators are looking into the cause. No injuries were reported and the building was unoccupied at the time of the fire.