A colossal earthquake that caused damage from South Carolina to Washington D.C. and temporarily reversed the course of the Mississippi River nearly two centuries ago could be repeated within the next 50 years, scientists said today. Strain is building on a fault near Memphis, Tennessee that was the site of a magnitude 8.1 earthquake in 1812, according to new observations that settle a debate on the risk of another huge quake. The odds of another 8.0 event within 50 years are between 7 and 10 percent, geologists said today. The assessment, based on new data from a recently installed array...