No, there will be no mass death; for one thing, there won’t be “masses” of whites anymore anyway (since they won’t breed). Also, non-whites look at how formerly white areas quickly degenerate into primitive pre-industrial wastelands, and know they can’t live without electricity, sewage, and people willing to work.
Instead, we’ll remain where we are now: Whites working to pay for everything for non-whites, and opting for self-imposed extinction rather than fighting it.
Hatred is more powerful than a desire for sewage treatment. Things will return to subsistence farming, supplemented by hunting small rodents.