All the links herein come from www.channel4.com, a british site with a plethora of information. This is definitely going in the "We Remember" Section.
In 1666 a fire blazed through London. It started on Pudding Lane and spread far and wide, consuming everything in it's path. The fire raged for four days and four nights, consuming city landmarks like St. Paul's Cathedral and Guildhall, before gunpowder blasts finally halted the fire's progress. After the fire, more the 13,000 homes and 87 churches had burnt to the ground. Amazingly though, there were only 5 recorded deaths due to the fire.
Though the fire cost London upwards of £10,000,000 at a time when the city's annual income was around £12,000, a number of good things came out of it. King Charles II, who's father, King Charles I, had inspired an uprising of civil war among the city during his reign, showed his loyalty to his citizens, and personally oversaw the quick and efficient rebuilding of the city. London, which had formerly been built mostly of thatch and wood, was rebuilt in stone, and was able to do some slight redesign of the city to better accomodate the city. New awareness of the dangers of fire eventually inspired better fire safety codes. The fire also helped slow the spread of the Plague by killing or driving off large numbers of the rats that carried the plague-ridden fleas.
Information was gotten from this amazing site that even includes a flash map that shows the spread of the fire. I didn't truly grasp how large the fire was until I watch the fire spread demonstration. It also includes links to a ton of information of the subject, and names of books to read about it.