During the Great Depression, control was purchased by heirs of the du Pont family. After 30 years of fragile financial condition, the FEC, under leadership of a new president, Ed Ball, took on the labor unions. Ball claimed the company could not afford the same costs as larger Class 1 railroads and needed to invest saved funds in its infrastructure, the condition of which was fast becoming a safety issue. The company—using replacement workers—and some of its employees engaged from 1963 until 1977 in one of the longest and more violent labor conflicts of the 20th century. Ultimately, federal authorities had to intervene to stop the violence, which included bombings, shootings and vandalism. However, the courts ruled in the FEC's favor with regard to the right to employ strikebreakers. During this time Ball invested heavily in numerous steps to improve the railroad's physical plant, and installed various forms of automation. The FEC was the first US railroad to operate two-man train crews, eliminate cabooses, and end all of its passenger services (which were unprofitable) by 1968.