Then another person appears, also close to drowning, and again they pull them out. This happens all afternoon and the couple get more and more tired from constantly rescuing people from the river. Eventually they think: “we need to go upstream and find out why so many people are falling in the river.”
When they go upstream, they discover that people are being drawn to the edge of a cliff to look at the river but there is no safe way to do this. People keep falling in. The couple work with the local community to build a fence to keep people from falling in the river. Occasionally, a few still fall in but it is a lot less than before.
As this story demonstrates, investing upstream in prevention rather than downstream in intervention is often wiser and more effective. This philosophy is the essence of public health.