"What happens to those who never get a chance to hear the Gospel and die before they do get a chance?"
No one will go to Hell because they haven't heard of Jesus. They will be condemned for murder, rape, adultery, fornication, lying, stealing, etc. Put your concern for others to hear the gospel aside for the moment. If you died right now you will justly end up in Hell. Get right with God and become a missionary, if you really care about the lost.