In 1184, a number of nobles gathered at the Church of St. Peter in Erfurt, Duchy of Thuringia. Things did not end well.
A feud between Louis III, Landgrave of Thuringia and Archbishop Conrad of Mainz which had existed since the defeat of Henry the Lion intensified to the point that King Heinrich VI was forced to intervene while he was traveling through the region during a military campaign against Poland. Heinrich decided to call a diet in Erfurt where he was staying to mediate the situation between the two and invited a number of other figures to the negotiations.
Nobles across the Holy Roman Empire were invited to the meeting, and many arrived on 25 July to attend. Just as the assembly began, the wooden floor of the provost of St. Mary, in which the nobles were sitting, broke under the stress, and people fell down through the first floor into the latrine in the cellar. About 60 people died, including Count Friderich of Abinberc, Count Heinrich of Thuringia, Count Gozmar (de) of Hesse, Count Friderich of Kirchberg, and Burchard of Wartburg. King Heinrich was said to have survived only because he sat in an alcove with a stone floor.