classes until the month of december. we're following that. we're in denver. what's the story? >> the district superintendent says they have never had to shut it all down due to illness but in recent weeks hundreds and hundreds of students, teachers, and staff have all had to call in sick because they were becoming ill with similar symptoms, that is vomiting that comes on rapidly. the district has 22,000 students and close to 2800 teachers and staff members. in a statement the nursing coordinator for the school district said we're taking this highly unusual action because this virus is extremely contagious and spreading quickly across our schools. in addition it appears that there is now a second related virus that is affecting students. some of whom have already been ill in recent weeks. the combination of the two has created an unprecedented spread of illness. county health officials say this is likely a norovirus