Watertown Fire Rescue responded to a bale fire about a mile southeast of Watertown early Monday morning, around 5:00 am. Upon arrival, several bales inside a bale storage shed were engulfed. Approximately 150 bales were lost in the fire out of the roughly 500 being stored. The cause of the fire appears to be of natural spontaneous combustion, a fairly common occurrence in bale pile storage facilities. The fire was reported by a passerby. Along with the bale pile owner and several neighbors, Watertown Fire Rescue assisted in extinguishing the fire. There were no injuries reported while working the fire. Watertown Fire Rescue would like to sincerely thank all of the neighbors involved for their time and effort in extinguishing the fire. Please remember to bale hay under 20% moisture if possible, use a preservative to cut down on bacterial growth inside a bale, and keep hay covered as much as possible. Also, monitor the internal temperature of the bale pile. Thanks and have a great day. WFR.