That teacher(s) should be on the street, along with any administrator who was aware of the lesson.
Every pro 2A lawyer in that school district should file law suits for every pro 2A citizen against the teacher(s) involved, the school administrators, the school district and the Board of Education.
Everyone should picket the school, fill the PTA and Board meetings with concerned citizens who just won't go away.
I'd say to strike the school and keep the kids home, but unless you start home schooling, the missed days could cause them trouble.