What calamity struck London in the year 1666?

Okay, let's talk about the Great Fire of London. In 1666, London was a very different place than it is today. Most buildings were made of wood and were crammed closely together. Sanitation was poor, and fire safety wasn't really a thing. The fire started in a baker's shop on Pudding Lane on September 2nd and raged for four days. Strong winds helped it spread rapidly, consuming much of the city. Now, while the plague was a devastating event in London's history, that was in 1665, the year before the fire. Flooding is always a risk in London, but there wasn't a major flood event in 1666. And nuclear power wasn't even invented until the 20th century, so a nuclear plant disaster is completely out of the question. The Great Fire of London is a significant event because it led to the rebuilding of London with stricter building codes, wider streets, and brick or stone construction, which helped to prevent similar disasters in the future. So, the calamity that struck London in 1666 was definitely the fire.