Three of the observers eventually died of conditions that are known to be promoted by radiation: Graves of a heart attack 20 years later at age 55; Cieslicki of acute myeloid leukemia 19 years later at age 42; and Young of aplastic anemia and bacterial infection of the heart lining 27 years later at age 83. Some of those deaths were probably latent stochastic (random) effects of the accident; it is not possible to draw any definitive conclusions from such a small sample set.