ELK POINT, S.D. (AP) – Multiple agencies continue to search for the body of a college student from Iowa who presumably drowned in the Missouri River in South Dakota while trying to help others. Union County (South Dakota) Sheriff Dan Limoges tells the Argus Leader that boats are still “going out every day.” Twenty-three-year-old Tom Patterson, of Frostburg, Maryland, was swimming with friends on Sept. 4 southwest of Elk Point (SD) when he disappeared.

Authorities have said that information from a witness indicates Patterson was trying to help other swimmers back to shore when he was swept away by the current. Limoges says the South Dakota Game, Fish and Parks Department and its Nebraska counterpart are involved in the search. He says an airplane has flown over the area for three days.

Patterson had been attending Briar Cliff University.