The Erfurt latrine disaster (German: Erfurter Latrinensturz, lit. 'Erfurt latrine fall') occurred on 26 July 1184 in the German city of Erfurt. Henry VI, then the King of Germany, was conducting a Hoftag ("court day") with local nobility on the second floor of a building. The combined weight of the assembled attendees caused the floor of the building to collapse through the ground floor and into the latrine cesspit below. Sources say that approximately sixty attendees died, some of whom drowned in human waste after falling into the cesspit.
They were meeting on the second floor but the beams were rotten so it broke. The weight of everyone and the debris then also broke the ground floor and some of them fell into the cesspit.
Ever been near an outhouse? You can smell them from a ways off. Even two stories up it was probably a pretty rank meeting room.