Sweet Auburn was designated a National Historic Landmark in 1976. However, like so many other inner-city neighborhoods, Sweet Auburn fell victim to lack of investment, heavy, widespread crime, homelessness, and abandonment, compounded by construction of the Downtown Connector freeway that split it in two. In 1992 the National Trust for Historic Preservation recognized that it was one of America's 11 Most Endangered Historic Places and, in 2005, the Georgia Trust for Historic Preservation included the area in its 2006 list of "Places in Peril". The Historic District Development Corporation (HDDC) was formed to turn the trend around, starting with houses surrounding the birth home of Dr. Martin Luther King Jr., and working outward. In 2014, the city of Atlanta completed the installation of the Atlanta Streetcar, a line that creates a loop connecting the Martin Luther King Jr. National Historical Park to downtown and the tourist attractions of Centennial Olympic Park. The streetcar travels east along Edgewood Avenue and west along Auburn Avenue.