destruction or slaughter on a mass scale, especially caused by fire or nuclear war. Concentration camp, internment centre for political prisoners and members of national or minority groups who are confined for reasons of state security, exploitation, or punishment, usually by executive decree or military order. Wall street exchange is the world's biggest stock exchange. On a single day 24 october 1929 , 13 million shares were sold . Over the next three years the between 1929 - 1932 the national income of USA fell by half.