In Europe, an extremely rare form of E. coli is responsible for one of the largest outbreaks of the disease ever recorded. 17 people have died in Germany and more than 1500 sickened. And there have been more cases reported in 8 other European countries. It's still a mystery exactly what caused the outbreak, but officials suspect it came from either raw lettuce, tomatoes or cucumbers. What is it that makes this strain worse than normal? Madeleine speaks to Sarah Klein, a food safety attorney at the Center for Science in the Public Interest.