Donora is a borough in Washington County, Pennsylvania, 20 miles (32 km) south of Pittsburgh on the Monongahela river. Donora was incorporated in 1901. Donora got its name from a combination of William Donner and Nora Mellon, banker Andrew W. Mellon's wife. Agriculture, coal-mining, steel-making, wire-making, and other industries were conducted in Donora early in its history. In 1910, 8,174 people lived there; in 1920, 14,131; and in 1940, 13,180 people lived in Donora.