FONTANELLE, Iowa (AP) — Iowa officials say there could be reason to cry over the spilling of a lot of milk — at least some of which made its way into a southeastern Iowa river.

The Iowa Department of Natural Resources said Tuesday in a news release that the crash of a tanker hauling milk east of Fontanelle Sunday evening caused the spill. Officials say the tanker could have been carrying 7,500 gallons of milk, and that the tanker was almost empty when it was hauled away.

DNR officials say heavy milk concentrations can cause fish kills in streams. Investigators who arrived Monday found milk in a road ditch flowing into an unnamed tributary. From there, the milk ran into the Middle Nodaway River, creating a visible plume.