In June, firefighters who responded to a barn fire located near the Indiana/Michigan border subsequently developed diarrhea, gas, bloating, and abdominal cramps. Local hydrant water and onsite swimming pond water were used to extinguish the fire. Firefighters from Indiana and Michigan responded. Three of the twenty known illnesses were confirmed to be caused by Cryptosporidium parvum. Cryptosporidium was found in calf fecal samples, and the farm's swimming pond. Cases were statistically more likely to have had direct contact with calves. Cases from the responding fire station in Indiana had exposure to pond water through drinking or washing themselves, or drunk from a cooler filled with water from an undetermined source.