Holy Roman Empire

In July 1518, a woman in Strasbourg, Holy Roman Empire, began to dance for no reason. The dancing spread like an epidemic—by August, about 400 people could not stop. Doctors, unable to determine the cause, could only wait for them to collapse from exhaustion.

In 1184, nobles of the Holy Roman Empire gathered in Erfurt for a land dispute mediation. The second floor collapsed under their weight, then the first floor gave way too, plunging about 60 nobles and attendants into the underground toilet cesspit, where they drowned.