Before the school year began, Massachusetts health authorities recommended that schools close only as a last resort during flu season and instead focus on keeping sick students isolated at home. Grafton school and public health officials were in close contact with the state health department before today's action, Manley said.
"It is a decision that is made locally," she said.
http://www.boston.com/news/health/blog/2009/10/suspected_swine_2.html
This is a decision that was made locally, however given the circumstances and the little knowledge about H1N1 it's important to protect the health of the students and faculty. Closing the school might be a better alternative than the latter news.