Southeast Chicago and northwest Indiana contain the remnants of what was once a vibrant center of the steel industry. Steel mills once blanketed the entire lakeshore south of 79th Street and the banks of the Calumet River, but the mills have all disappeared since the 1970s. For example, U.S. Steel's South Works, which once employed over 17,000 workers and occupied over 800 acres north of Calumet Park, closed in 1993. To hear former steel worker and labor activist Ed Sadlowski describe the steel industry click here: Ed Sadlowski Describes the Steel Industry The neighborhood experienced many labor struggles, such as the infamous 1937 Memorial Day Massacre at Republic Steel, and has undergone continual racial and ethnic succession, as earlier immigrants moved to outlying areas and newer immigrant groups replaced them in the industrial core of the district.