With the beginning of World War II, the poor white classes vanished, and the need for a black workforce in the mines and factories made domestic work the province of women. In all of South Africa, men in 1910 were 45 percent of all domestics, but only one domestic in twenty was white. In tropical Africa, the domestics in a colonial house were abundant and specialized, but the number of whites was always very small. In a society in which most people's incomes do not permit them to hire salaried workers, invisible domestic work has become the rule. The most typical case was that of migrant workers, young salaried unmarried men traditionally unused to doing domestic work, who went to the city with a little girl or young woman from their families to help them in their households. They arrived in groups, led by adults who said that they were their relatives, but the phenomenon begins to suggest organized trafficking.