Not to sound like an old geezer or anything, but you shouldn't have brought it to school in the first place.
School=Place for learning
Yeah, I agree. The most valuable thing I bring to school is my lunch money, but the school has this password system (you put money on your account so it doesn't get stolen) so really I never lose anything valuable. (Well, I did lose my hood once, I have no idea how that happened).
School=Place for learning not for bringing in expensive stuff.