The formation of blood cells(red blood cells, white blood cells, platelets etc) takes place in bone marrow. If bone marrow is destroyed there will be no formation of blood cells or either abnormal blood cells will be formed. When red blood cells are destroyed a person suffers from anaemia, fatigue and loss of breath which may leads to death. If white blood cells are affected it leads to infections and fever. Similarly if platelets are destroyed, the ability of blood clotting will be lost.