Researchers do not know how the girl died, but since there were no signs of trauma on the remains, it appears she likely perished from disease. Terpstra said the three most likely culprits would have been malaria, tuberculosis and smallpox, which had just appeared during the second century. He ruled out leprosy, which would have shown up on the skeleton, he said. Life expectancy at the time was about 25 years, Terpstra said, and only about half of all children made it to age 10.