Lloyd's of London has issued its City Risk Index 2015-2025, which looks at 18 emerging, manmade and natural threats and rates their potential impact on the gross domestic product of 301 major cities around the world. The study, done in cooperation with Cambridge University, found that, overall, risks including earthquakes, market crashes and cyber attacks posed a $4.56 trillion threat to the 301 cities, with the Top 20 accounting for 35% of that. View the gallery
On Aug. 29, 2005, Hurricane Katrina brought Category 5 strength -- winds topping 175 mph -- to the U.S. Gulf Coast. After landfall, 135-mph winds and the resulting storm surge devastated cities from Biloxi, Mississippi, to New Orleans, Louisiana, killing more than 1,800, displacing 1.5 million and causing damages estimated up to $150 million. A look back: View the gallery