 That increased the number of offices of the firm from nine to 28, but cultural and style differences between the parent company's traditional engineering management and retail brokerage management led to an exodus of key employees, and the Securities firm closed its doors in 1974.Stone & Webster's difficulties with constructing conventional power plants were matched by its problems in nuclear construction.By the late 1970s, the company had attained a central role in the nuclear power industry—a significant portion of all nuclear energy in the United States was being generated at plants designed and generated by Stone & Webster.