Several residents of Strasburg
Danced themselves to death in 1518
For some reason, a woman named Frau Troffea took to the streets of Strasburg and began doing a jovial dance. She danced for a solid 6 days straight.
After that week, she was joined by 34 other townsfolk. A month later, nearly 400 people were dancing, with 15 dying per day due to exhaustion, heart attacks and strokes.
To date, no one knows the reason for “the dancing plague,” and if they were really dancing happily or just having a mass seizure.