Scar Island by Dan Gemeinhart

The cover is more light-hearted than the book.

Jonathan has been sent to a reformatory school called Slabhenge on a remote island.  The head master is cruel and abusive of the boys, but Jonathan is so haunted with guilt because of his "crime" he meekly accepts all punishments.  When a freak accident kills all the adults on the island, a social order quickly arises, with a boy, just as cruel as the old head master, at its head.  Jonathan goes along with things at first, but soon finds himself defending other boys and standing up to the leader.  He also begins to realize that their island holds a terrible secret that threatens all their lives. 

When I started this book I thought to myself, I hope this doesn't end out to be another Lord of the Flies.  It did, kind of.  It is a little toned down compared to Lord of the Flies.  The head bully keeps threatening to do terrible things, but something always interrupts the course of events to prevent them from happening.  So the reader gets the idea of intimidation, without having to see the acts of abuse.  This is a good choice for young readers who like a pretty intense psychological drama, with a bunch of mortal peril added in.  It reminded me of The Girl Who Owned a City by Nelson, not in plot but in tone. (249 p)