The failure of the dams came as a big surprise. Johnstown had constructed an entire system designed to completely eliminate the flood risk. In addition, regular inspections had turned up no defects. Still, the dams were no match for the thunderstorm that stalled over the area on July 20.
Common types of blood cancer include: 1  Leukemia: Cancer that originates in blood-forming tissue. 2  Non-Hodgkin lymphoma: Cancer that develops in the lymphatic system from cells called lymphocytes, a type of white blood cell that helps the body fight infections. Non-Hodgkin lymphoma: Cancer that develops in the lymphatic system from cells called lymphocytes, a type of white blood cell that helps the body fight infections. 2  Hodgkin lymphoma: Cancer that develops in the lymphatic system from cells called lymphocytes.
Blood cancers affect the production and function of your blood cells. Most of these cancers start in your bone marrow where blood is produced. Stem cells in your bone marrow mature and develop into three types of blood cells: red blood cells, white blood cells, or platelets.