However, the Jack in the Box fast-food restaurant chain had knowledge of but disregarded Washington state laws which required burgers to be cooked to 155 °F (68 °C), the temperature necessary to completely kill E. coli. Instead, it adhered to the federal standard of 140 °F (60 °C). If Jack in the Box followed the state cooking standard, the outbreak would have been prevented, according to court documents and experts from the Washington State Health Department.
And this was entirely preventable