Green’s Dictionary of Slang

to be the first black family to move into a formerly all-white inner city area.

1952		Lait & Mortimer USA Confidential 61: Their neighborhoods are block-busted by Negroes.
1966		N.Y. Times 21 July 29: Speculators [...] have just begun to appear on the Concourse. ‘They’ve started to blockbust some buildings here,’ said an aide.
1967		R. Conot Rivers of Blood 449: Despite white anguish, along the edge of the ghetto another few blocks are ‘busted.’ Once two or three Negroes have moved in, it becomes impossible to sell a house to a white person.
1986		T. Philbin Under Cover 2: In the sixties, the blacks had tried to blockbust, and some found out the hard way [...] Four blacks were found dead in cellars.