In 1518, somewhere between 50 and 400 people in Strasbourg danced for days, and later chronicles claimed as many as 15 died each day, in what remains one of history's most documented and least explained suspected mass psychogenic outbreaks

In 1518, somewhere between 50 and 400 people in Strasbourg danced for days, and later chronicles claimed as many as 15 died each day, in what remains one of history's most documented and least explained suspected mass psychogenic outbreaks

A woman started dancing in the street, and the city's answer was to hire musicians. Its own records tell a smaller, stranger story than the legend. And one researcher thinks it looked more like a ritual than an illness.