A 4-year-old was left behind during a recent Marshall public school field trip. District administrators in Marshall will now be reviewing field trip protocols after the child was left at the Children’s Museum of South Dakota in Brookings on Tuesday. Teachers didn’t realize the 4-year-old was missing until they were back in Marshall, about an hour away. Marshall Superintendent Klint Willert has offered an apology, and says that rules for field trips were not followed. He says students are supposed to be counted before they get on the bus and again after they’ve boarded.