St. Lucia's flood: The Zuiderzee sea wall in the Netherlands collapses, killing over 50,000 people.
St. Lucia's flood (Sint-Luciavloed) was a storm tide that affected the Netherlands and Northern Germany on 13/14 December 1287 (OS), St. Lucia Day and the day after, killing approximately 50,000 to 80,000 people in one of the largest floods in recorded history.
This disaster was similar to the North Sea flood of 1953, when an intense European windstorm coinciding with a high tide caused a huge storm surge. The St. Lucia flood had a major influence on the subsequent history of the Netherlands.