private void destroyBoxes() {
        Iterator<Box> i = BombermanGame.level.iterator();

        //destroy boxes
        while (i.hasNext()) {
            Box box = i.next();
            if (!box.isBreakable()) continue;

            if ((x == box.x) && (y == box.y + BOX_SIZE || y == box.y - BOX_SIZE)) {
                i.remove();
            }

            if ((y == box.y) && (x == box.x + BOX_SIZE || x == box.x - BOX_SIZE)) {
                i.remove();
            }
        }
    }