The "crash" was the Wall Street stock market crash of October 1929 that led to The Great Depression, a severe worldwide economic depression in the decade before the Second World War.
The Great Depression had devastating effects on virtually every country and every social class. Incomes, savings, tax revenues, profits and prices dropped, and international trade plunged. Unemployment in the US rose to 25%, and in some countries as high as 33%.
Construction was virtually halted in many countries. Farming and rural areas suffered as crop prices fell by 60%. Areas dependent on primary sector industries (cash cropping, mining and logging) suffered the most.