Overview: Dr. Sanjay Gupta investigates the safety of the nation's food supply, which the CDC estimates is responsible for causing some 76 million people to become sick every year, with an approximate 325,000 requiring hospitalization and 5,000 dying. Included: an interview with Dr. Robert E. Brackett, the director of the FDA's Center for Food Safety and Applied Nutrition; the experiences of a family who became ill after eating E. coli-contaminated greens.