 During the second decade of the 20th century, the ocean liner RMS Titanic sank after striking an iceberg on her maiden voyage from England to New York. The personal income tax became law under the 16th Amendment. A year later, World War I broke out in Europe and women were granted the right to vote when the 19th Amendment was adopted. In science, Danish physicist Niels Bohr won the Nobel Prize for his services in the investigation of the structure of atoms and of the radiation emanating from them. Although the Bohr model of the atom has been replaced by other models, its underlying principles still remain valid today. In health physics, the British Renkin Society adopted formal radiation protection recommendations for X-ray users.