On July 2, 1934, Marie Curie died at the Sancellemoz sanatorium from aplastic anaemia — radiation poisoning accumulated over four decades of work with substances she had helped discover. She was 66.

The cause of death was not a mystery. Her laboratory notebooks remain so radioactive that researchers who want to examine them must sign a liability waiver and work in protective gear. They are kept in lead-lined boxes in the Bibliothèque nationale de France.

Curie had been the first person — not the first woman, the first person — to win Nobel Prizes in two different sciences: Physics in 1903 for the discovery of radioactivity, Chemistry in 1911 for isolating radium and polonium. When she was nominated for the first, the Swedish Academy initially planned to recognize only Pierre Curie and Henri Becquerel. Pierre refused to accept without her name on the prize.

The 1911 prize she accepted alone. Pierre had been killed by a horse-drawn cart in 1906. By 1911 the French press was running stories about her affair with physicist Paul Langevin and urging her to return to Poland.

She did not return. She finished her work. Her daughter Irène Joliot-Curie would win a Nobel Prize of her own in 1935, the year after her mother's death.