Two separate anhydrous ammonia leaks this week led to the deaths of at least 100-fish in Harrison County. But officials say it could have been worse…had it not been for the help of some beavers. Officials with the Iowa Department of Natural Resources say a semi-truck owned by Terra Express of Sioux City, was pulling a tank filled with anhydrous ammonia, when it rolled into a creek East of Woodbine Tuesday, leaking a vaporous cloud. When emergency crews used water to knock-down the cloud, the contaminated water entered the stream, where it was contained thanks to a beaver dam and and additional dam built Tuesday night. The barriers held the contaminated water to a 150-yard stretch of the creek. Officials say as the truck and tank were being towed from the creek Wednesday, the tank began to leak, and another vapor cloud formed. At least 100-fish were killed in the containment area, including bluegills, crappie, and minnows. The contaminated water has since been pumped out of the creek and is being applied to area farm fields. the D-N-R’s Dan Stipe says if it weren’t for the beaver dam, the fishkill could have been a lot worse.