Cnidaria is a phylum within Kingdom Animalia which consists of hydras, jellies (or jellyfish), sea anemones, and corals. All cnidarians are radially symmetrical, and there are two main radially symmetrical body types.
The stock market crash, on black Tuesday (October 29, 1929) began the Great Depression.
October 29, 1929, was a dark day in history. Black Tuesday is the day that the stock market crashed, officially setting off the Great Depression. Unemployment skyrocketed--a quarter of the workforce was without jobs by 1933 and many people became homeless.