The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World

by Steven Johnson

Radcliffe and Whitehead, along with other investigators, quickly uncovered a number of negligent practices at the East London company that had allowed the nearby River Lea to contaminate the groundwater around the company’s reservoir at Old Ford. Eventually, the index cases at Bromley-by-Bow were tracked down; the doomed couple’s water closet turned out to empty into the River Lea less than a mile from the Old Ford reservoir. In the end, the link to the East London water supply proved to be even more statistically pronounced than the link to the Broad Street pump had been in 1854. Ninety-three percent of the dead were eventually found to be East London Water customers.