The bug was later traced to undercooked hamburger served at Jack in the Box restaurants. This outbreak thrust foodborne illness onto the national stage as a real and present threat, sparking a sea change in the way Americans and the government treat this issue. To commemorate the 20th anniversary of the 1993 Jack in the Box outbreak, Food Safety News has produced a series of retrospective stories chronicling the outbreak itself and how food safety in America has changed since that time.