In HaRav Aharon Feldman shlita book, "The Eye of the Storm", in the chapter entitled, "The Chazon Ish", Rav Feldman lists some questions that were asked to the Chazon Ish. One of them is, May a Rosh Yeshiva expel a student who has a harmful influence on his friends, if there is a chance that he will become non observant by consequence? Rav Feldman does not answer this question. How did the Chazon Ish rule in this case and where can I find the answer?