I need help with developing a crisis communication plan for the following scenario: Half the senior class in your private magnet high school cheated

I need help with developing a crisis communication plan for the following scenario:

Half the senior class in your private magnet high school cheated on the graduation exam, and the rest were apparently aware of the cheating, as were many of the parents. An employee, a secretary with several employee passwords, allegedly gained access to the exam before its release and provided the questions and responses to her son, who then provided it to his friends. The employee was often provided login names and passwords to facilitate records processing for several administrators when they were off site, often at conferences. Headquarters wants to minimize the publicity but cannot in good faith issue diplomas to students who cheated. The employee has been dismissed for conduct, and an investigation is underway, but graduation is next week and the evidence against the cheating seniors is clear. They won't be receiving their diplomas unless they pass an alternate version of the test that won't be ready for sixty days. You represent Educational Services, Inc