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.
Hematologic malignancy Hematological malignancies are cancers that affect the blood and lymph system. The cancer may begin in blood-forming tissue (e.g., bone marrow), or in the cells of the immune system. Some types of hematologic malignancies include: Leukemia; Non-Hodgkin lymphoma; Hodgkin lymphoma; Multiple myeloma; For more information about hematologic malignancies, including common symptoms and treatment options, see blood cancers.