World Disasters

I am currently working on a history project and need examples that involve something good stemming from disasters. For example, canned goods were invented to preserve food being shipped to soldiers during wartime, the advent of modern day nursing began during the Civil War opening a door for women to work in the medical field, and sonar was invented during World War 2 to detect enemy submarines, but afterward was used to map ocean topography. I realize all three of these examples relate to war, but any disaster--whether it be natural or manmade--would fit into this project. Thanks for you help!