It was the summer of 1972, and Tom Brucker was in a tight spot two generations in the making. His father Roger had created a nonprofit dedicated to the research of caves (aptly named the Cave Research Foundation) alongside colleagues who were exploring the Floyd Collins Crystal Cave in the 1950s — one of the main gateways to the Flint Ridge Cave System. Two decades later, the younger Brucker was squeezing through an extremely narrow passage deep inside Flint Ridge, considered the longest cave system in the world at the time, in an effort to see if it might connect with the similarly spectacular and storied Mammoth Cave system.
In an earlier expedition that summer, cave explorer Patricia Crowther had already made it through the same tight spot — a roughly 35-foot-long passage that stood near the end of what was then thought to be the longest stretch of the Flint Ridge system. Crowther had come to a waterfall tumbling down a pit at the end of the squeeze, but lacked the equipment at the time to continue.