What happened when the school caught on fire?

The Lost Boy is the second in a trilogy of books that tell the story of author Dave Pelzer's childhood. In this book, with the help of his teachers, young David is finally able to escape the household of his abusive mother and is put into the foster care system.
The first "permanent" foster parents that David goes to live with are Lillian and Rudy Catanze. While his life with the Catanzes is better than he has ever had before, David's past of severe abuse has not set him up to be emotionally stable, and he starts misbehaving, acting out, and doing some petty shoplifting. A fellow classmate named John accepts David into his gang, and decides that to be initiated, David must do something like flattening someone's tires or setting fire to a classroom. Too afraid to say no or to tell an adult what John plans on doing, David passively agrees that he'll set fire to Mr. Smith's classroom with John.
However, it ends up being just John alone that sets a room on fire. David comes upon the scene when the fire is already out of control, with John screaming, “Come on, man, help me! Help me put out the fire!” John runs away, and David tries to stop the fire, dangerously pulling out a can of lighter fluid from the vent where John put it. Eventually David calls out to a girl in the hallway to pull the fire alarm, and pours gravel over the fire to smother it until fire trucks come to save the day. At that point, David flees the building.
Sadly, even though John and David agree to deny that either of them were involved with the fire, John betrays David and tells the principal that the fire was David's idea and that David started the flames. Because he is now believed to be an arsonist, on top of being a thief, David is taken to a juvenile detention center called Hillcrest.