On Wednesday morning, Grant County deputies and the Richland Bomb Squad responded to reports of a suspicious package at Con Agra Foods Lamb Weston in Quincy.
The suspicious package was found at about 4:30 a.m. in the plant's potato storage facility. Everyone from the building was evacuated as a preliminary precaution.
At around 7 a.m., the bomb squad determined the suspicious package was an unexploded military mortar round.
Sergeant Paul Snyder said it was probably gathered in a potato field and accidentally brought inside.
The mortar round was detonated as a precaution.