§ What happened
Cross connections at two hotels allowed sewage to enter the potable water system.
Visitors became infected with amoebic dysentery but did not show symptoms until after leaving Chicago.
City officials attempted to suppress reports of illness while the World's Fair continued.
Nearly 100 deaths and over 1,700 illnesses across 206 cities were eventually traced to the hotels.
Why it matters
The incident remains one of the earliest well-documented examples of illness and death caused by cross connections in a public water supply.
◇ Prevention lesson
Proper cross-connection control and functioning backflow preventers are essential to protect potable water from contamination.