Spoiler : Polish born...married into French...died because of her research....Fantastic life. She died from prolonged exposure to radiation. Her many years working with radioactive materials took a toll on her health - although the official recorded cause of death was aplastic anemia. Her husband died in a street accident, but it's likely he would have eventually died from the effects of radiation, as did their daughter and her husband. Even now, all their papers from the 1890s, are too dangerous to touch. Their laboratory books are kept in special lead boxes and people who want to see them have to wear protective clothing.