In the 1960's, the City of Halifax decided to remove an area that they had determined to be a "slum." By 1970, the vibrant thriving community of Africville would be gone, and many of its citizens would not recover. 

Sources: 

Jennifer Nelson: Razing Africville 

Dakshana Bascaramurty: On Africville, the razing and the racism (link: https://www.theglobeandmail.com/politics/article-africville-canada-news-coverage/) 

Albert Rose: Report of a Visit to Halifax with Particular Respect to Africville 

Shelagh Mackenzie: Remember Africville