Authorities reportedly responded to the scene and discovered three deceased individuals: 42-year-old Tyler Schmidt, 42-year-old Sarah Schmidt, and their 6-year-old daughter, Lula Schmidt. The adult victims' 9-year-old son survived the attack at the campground and was found by a park guest, KCCI-TV reports.
The Department of Public Safety said authorities later discovered a camper that was unaccounted for, and after a search of the area, they located Anthony Sherwin, who was also deceased. He reportedly died from a self-inflicted gunshot wound.
The Iowa Office of the State Medical Examiner will perform autopsies for the three victims, according to the Department of Public Safety.