On this day, 6 June 1966, a team of 21 US military scientists released around 87 trillion bacteria spores into the New York City subway, to simulate a biological weapon attack. They broke lightbulbs on gratings on the seventh and eighth avenue lines in the first in a series of tests on unsuspecting members of the public. By June 10, a million New Yorkers had been exposed. It was just one of scores of biological and chemical warfare experiments carried out on US civilians during the Cold War.
Pictured: the NYC subway, 1966 https://www.facebook.com/workingclasshistory/photos/a.296224173896073/1733393696845773/?type=3