Authorities have released the name of the person killed in the only known fatality from the flooding that’s ravaged southeastern South Dakota over the past week. Merlyn D. Rennich, 87, was killed Saturday afternoon after driving a 2013 Kawasaki Mule all-terrain vehicle north onto a closed section of 480th Avenue from 273rd Street, about 5 miles northeast of Harrisburg. The east shoulder of the road had washed away in the flooding. According to a news release from the state Department of Public Safety, Rennich went backward over the edge of the washout, the vehicle began to roll, and Rennich was ejected.