Federal health authorities have determined responsibility for the vast 26-state outbreak of Listeria in cantaloupes, almost three months  — and 123 illnesses, 25 deaths and one miscarriage –  since it began.

In a long report released this week, they say they found Listeria not in the fields where the melons were grown, but in the packing and cold storage facilities on the single large farm where they all came from; and, in addition, they identified some practices on the farm that may have caused Listeria contamination or allowed it to multiply.

Just as a reminder of what was at stake here since...