After World War II, the modernized Lackawanna plant remained at near-wartime production levels and employed nearly 20,000 workers for several decades. Further modernized in the 1960s with basic oxygen furnaces, it sustained remarkable output into the 1970s and helped its parent company set 1973 production records of 23.7 million tons of raw steel and 16.3 million tons of finished steel, surpassing World War II totals. By the late 1970s, foreign competition, increased state property taxes, and new environmental regulations sharply reduced the facility's profitability, and by late 1977 the workforce had fallen to 8,500. Bethlehem Steel allowed the Lackawanna plant to become obsolete as it built a new facility in Burns Harbor, Indiana, and stopped investing in new steel production methods there. A nationwide recession in 1981 further reduced demand for durable goods and, along with high interest rates and the company's broader financial problems, made closure inevitable despite public efforts to reassess the plant's viability. On December 27, 1982, Bethlehem Steel announced that it would permanently shut down steelmaking at the facility. Workers were laid off in waves and many others were transferred, and in October 1983 the last steel was processed, costing more than 3,900 workers their jobs. After 80 years of operation, the plant's closure brought soaring unemployment, sharply higher property taxes in Lackawanna, and a wider economic depression that rippled through Western New York for years.