Younger siblings

So my younger brother is a freshmen in high school. He is failing most of his classes and now is in trouble with his school for destroying 18 textbooks costing about $1,400. My parents seem to have no control over him anymore and are asking me to step in and help. what should I do to keep him from going down this bad track? he doesnt seem to care that he did something wrong but i am not sure how to get it through his head. Please help me before this destroys his future and my family. I am in college BTW.