Two cousins, 73-year-old Mary Taylor Adams and 75-year-old Julia Taylor, still remember attending Ozark Elementary School as kids in 1955.
They were excited to be part of the annual Dairy Day Parade, in which they would be riding on a float along with Julia's sister Anita.
They attended school for part of the day, ate lunch—which included generous helpings of potato salad—and then school was dismissed early for the festivities.
As the parade was about to start, people started getting sick.
"Something was definitely happening in Ozark," said Julia Taylor Adams.
Before long, the town's small hospital was overwhelmed, and the search was on to find out why so many people were falling ill.
Julia Taylor and Mary Taylor Adams recall that day in vivid detail, and shared their memories when the StoryCorps Mobile Tour came to Springfield, Missouri.