Mary Ann Kellerman

But what happened was that seven people died in the Chicago area and they realised that they had all taken Tylenol.

The first known victim was 12-year-old Mary Kellerman, who woke up in the morning complaining of a sore throat and a cold.

Her mum gave her Tylenol.

And within hours, she was dead.

In late September 1982, someone appears to have exploited that vulnerability, and within days, an ordinary bottle of pain reliever would become the instrument of one of the most terrifying crimes in American history.

The first known victim was twelve-year-old Mary Kellerman of Elk Grove Village, Illinois, a suburban community northwest of Chicago.

On the morning of Wednesday, September twenty-ninth, Mary was suffering from symptoms of a cold.

She had a runny nose and a sore throat.

The same poison connected her to the others.

By the time investigators pieced together the full scope of what had happened, seven victims had been identified.

Mary Kellerman, Adam, Stanley, and Theresa Janus, Mary McFarland, Mary Reiner, and Paula Prince.

They ranged from twelve to thirty-five years old.

It exposed a weakness in the entire system, and medicine had to change because of it.

September 29th, 1982, Elk Grove Village, Illinois, 12-year-old Mary Kellerman wakes up feeling sick.

Not dramatic.

She has some symptoms that, from a parent's perspective, are completely normal sick kid stuff.

The victims had unknowingly taken Tylenol capsules contaminated with deadly potassium cyanide.

They ranged in age from 12-year-old Mary Kellerman to 35-year-old Paula Prince.

Mary was rushed to the hospital on September 28th after taking a capsule for a cold.

She died shortly afterward.