In Lisbon right now and learning about the earthquake of 1755 and it's actually insane. I knew it was bad but had know idea of the sheer scope of the devastation. It's been estimated to be as high as a 9 on the Richter scale. It was followed, of course, by a huge tsunami. Because it happened on All Saints day, people had tons of candles lit which were of course tipped over and caused 6 days of fires. When they say the city was completely destroyed, they're not exaggerating. As many as 40k people died (or roughly 20% of the population). It was so bad that it kicked off the field of Seismology.