The agency said Wednesday that Betty Faye Word drove her Mercedes Benz into high water Tuesday night and it submerged. She did not escape.
At least 36 deaths have been reported from the large, stubborn storm system making its way through the South after cutting a destructive path through parts of the central U.S.
Mississippi and Arkansas saw the most fatalities, as well as the most destruction from violent tornadoes.
Deaths also were reported in Alabama, Tennessee, Oklahoma and Iowa.