Archimedes of Syracuse (287 BC – 212 BC) was an Ancient Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. He is generally considered the greatest mathematician of antiquity and one of the greatest of all time.
Archimedes was contemplating a mathematical diagram when the city of Syracuse was captured. A Roman soldier commanded him to come and meet General Marcellus but he declined, saying that he had to finish working on the problem. The soldier was enraged by this, and killed Archimedes with his sword. Plutarch also gives a lesser-known account of the death of Archimedes which suggests that he may have been killed while attempting to surrender to a Roman soldier. According to this story, Archimedes was carrying mathematical instruments, and was killed because the soldier thought that they were lethal weapons.
MORAL OF THE STORY: If an armed brute is talking to you, hide all the mathematical instruments you have.