The fire is said to have also helped to get rid of the Great Plague which had hit London in 1665, and killed about 70,000 of the 90,000 population, who may have died in the fire. We are able to know a lot about the great fire of London because Samuel Pepys wrote in his famous diary at the time. When the fire started, he looked out of his window, saw the fire and started writing about it. 