In the 1940s, urban Americans began a mass move to the suburbs in search of fresh air, elbow room and privacy. Suburbs began to sprawl out across the countryside, since most of those making the move were middleclass, they took with them the tax money the cities needed to maintain the neighborhood, in which they had lived. The people left in the cities were often those who were too old or too poor to move. Thus many cities began to fall into disrepair. Crime began to soar, and public transportation was neglected. (In the past sixty years, San Francisco is the only city in the United States to have completed a new mass transit system.) Meanwhile, housing construction costs continued to rise higher and higher. Middle-class housing was allowed to decay, and little new housing was constructed. Eventually, many downtown areas existed for business only. During the day they would be filled with people working in the offices and at night they would be deserted. Given these circumstances, some business executives began asking, 'Why bother with going downtown at all? Why not move the offices to the suburbs go that we can live and work in the same area?' Gradually some of the larger companies began to move out of the cities, with the result that urban centers declined even further and the suburbs expanded still more. This movement of business to the suburbs is not confined to the United States. Businesses have also been moving to the suburbs in Stockholm, Sweden, in Bonn, Germany, and in Brussels, Belgium as well. What did the city lose when those people moved out to the suburbs?