How did Leonardo da Vinci die?

His official cause of death isn't known. However, this looks like a good guess.

http://answers.yahoo.com/question/index?qid=20060828121731AAbaNpK

Leonardo da Vinci died on May 2, 1519. While the exact cause of his death is still the subject of debate among historians and scholars, it is widely believed that he died of natural causes, specifically a stroke. To find this information, you can consult various credible sources such as biographies, historical accounts, or scholarly articles about Leonardo da Vinci. Additionally, visiting museums or galleries dedicated to his life and work may provide further insight into the details surrounding his death.