Has happened before.
I grew up in Detroit in the Seventies and Eighties I have first hand memories of how this went.
https://en.wikipedia.org/wiki/Decline_of_Detroit
From the link:
conomic and social fallout of the 1967 riots
Per capita income in Detroit and surrounding region from the 2000 census. The dotted line represents the city boundary.
After the riots, thousands of small businesses closed permanently or relocated to safer neighborhoods, and the affected district lay in ruins for decades.[27]
Of the 1967 riots, politician Coleman Young, Detroit's first black mayor, wrote in 1994:
"The heaviest casualty, however, was the city. Detroit's losses went a hell of a lot deeper than the immediate toll of lives and buildings. The riot put Detroit on the fast track to economic desolation, mugging the city and making off with incalculable value in jobs, earnings taxes, corporate taxes, retail dollars, sales taxes, mortgages, interest, property taxes, development dollars, investment dollars, tourism dollars, and plain damn money. The money was carried out in the pockets of the businesses and the people who fled as fast as they could.
The white exodus from Detroit had been prodigiously steady prior to the riot, totally twenty-two thousand in 1966, but afterward, it was frantic. In 1967, with less than half the year remaining after the summer explosion, the outward population migration reached sixty-seven thousand. In 1968 the figure hit eighty-thousand, followed by forty-six thousand in 1969.[25]"