The Fond du Lac County Sheriff’s Office says the driver of a semi that rolled over on Highway 26 spilling tons of animal renderings may have fallen asleep. Sheriff’s captain Rick Olig says the accident happened early Wednesday morning on Highway 26 a couple miles north of Rosendale. Olig says the accident happened on a curve. But he says its not a sharp curve. "No its really not, its more of a gradual curve and the crash site is just north of a curve, that's why the indications are he (driver) may have fallen asleep," Olig told WFDL news. Olig says it was quite the mess with over 25 tons of animal waste parts strewn across the highway. "The truck was overturned and it was basically a pile of animal renderings laying the middle of the highway." The highway was closed for several hours to remove the semi and animal parts and rebuild the shoulder of the road.