In 1944, a small town in Illinois was gripped with fear that someone was spraying a toxic gas into their homes as they slept. And while there have been several explanations, there isn’t any one that’s recognized or accepted as the truth.
Research:

Percy Fawcett, Manuscript 512, and a Lost City in the Amazon, Pt. 2
37:10

Percy Fawcett, Manuscript 512, and a Lost City in the Amazon, Pt. 1
34:05

SYMHC Classics: Swill Milk
39:22