Responsible. University class committees have the obligation to reply to news and perform their duties. If you don't reply to the message, you will be responsible for the adverse consequences. However, due to some irresistible reasons (such as emergencies or personal problems), the class Committee cannot reply to the message and will not be responsible for it. Generally speaking, the university class Committee did not reply to the news, causing problems and should be responsible. But we should consider the specific situation and rationally evaluate the responsibility.