Twelve-year-old Mary Kellerman of Schaumburg, Illinois, fell ill on the morning of September 29, 1982 and was given an Extra-Strength Tylenol capsule by her parents. Hours later she was found unconscious on the bathroom floor, taken to a hospital and pronounced dead. Early speculation about a stroke gave way to a much darker finding: Mary’s death was later linked to cyanide-laced Tylenol capsules, making her the first known victim of the Chicago Tylenol poisonings.

In the days that followed six more people in the Chicago area died after taking contaminated Tylenol capsules. Investigators found lethal doses of potassium cyanide in multiple bottles, prompting a massive recall and industry changes including tamper-proof packaging and new federal anti-tampering laws. No one has been charged or convicted in the poisonings; a New York man, James William Lewis, was convicted of extortion for sending a letter claiming responsibility and demanding money, but he was not linked to the actual killings.

Did anyone in Schaumburg or the surrounding area at that time notice anything unusual about how over-the-counter medicines were handled or stored?