Cholera outbreak, Soho 1854
This kml contains the locations with numbers of deaths (3D polygons) and hand water pumps in Soho, derived from John Snow's investigation of the outbreak.
Switch on Names/Values to see actual numbers of deaths.
Data credit (Robin Wilson):
Boy: "I say Tommy, I'm blowed if there isn't a man a turning on the cholera."
Photo credit:

Broad Street pump
Photo and inscription: http://www.londonremembers.com/memorials/cholera-pump
Good site on the origins and impacts of the outbreak: http://www.ph.ucla.edu/epi/snow/snowcricketarticle.html

Deaths plot

Names/Values