Donnelly studied the story of floods and natural disasters from Egypt to Mexico. He studied things that had happened thousands of years ago. Then he wrote a book and explained his ideas He thought the story was about a real natural disaster. Perhaps there was a hurricane or an earthquake in the Atlantic Ocean near the island at this time. Perhaps it destroyed the island of Atlantis and all its people. Donnelly's book was very popular and more and more people started to think that the Island of Atlantis was a real place. They started to have different ideas about where it might be and what had happened to it