The North Sea Flood of 1953: Eyewitnesses give first hand testimony about the worst natural disaster to strike Britain in modern times. On 31 January 1953, a massive storm and its huge tidal surge flooded 250 square miles of land from the Shetlands to the Thames estuary, killing hundreds of people, sinking several ships, and destroying tens of thousands of homes. Few remember this disaster that shocked the country as it emerged from the trauma of World War II, but those who do remember it vividly.