It’s a mistake to blame density for the spread of the coronavirus. Cities, large and dense by definition, do not inevitably support explosive viral transmission. But factors that do seem to explain clusters of Covid-19 deaths in the United States are household crowding, poverty, racialized economic segregation and participation in the work force. The patterns of Covid-19 by neighborhood in New York City track historical redlining that some 80 years ago established a legacy of racial residential segregation.