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.
Leukemia, blood and immune system cancers. Leukemia is a cancer found in early blood-forming cells and is most often a cancer of the white blood cells. Leukemia is often classified as either chronic (progresses slowly) or acute (progresses quickly). Four main types of leukemia exist. Different types have different prognoses and treatments.