Who described the city as a place where "our physical contacts are close, but our social contacts are distant"?

According to Wirth, who was drawing on Simmel, "The close physical contact of numerous individuals necessarily produces a shift in the medium through which we orient ourselves to the urban milieu ... our physical contacts are close but our social contacts are distant." In other words, as the city intertwines and grows in a population that coexists with differences, co-ordination and organization is required.