Trying to run a codeigniter app but error 404 shows

dear seanf! my code and route is class News extends CI_Controller{

        public function __construct()
        {
            parent::__construct();
            $this->load->model('news_model');
        }

        public function index()

        {

            $data['news']= $this->news_model->get_news();
            $data['title'] = 'News archive';

            $this->load->view('templates/header',$data);
            $this->load->view('news/index',$data);
            $this->load->view('templates/footer');
        }

        public function view($slug)
        {   
            //$data['news'] = $this->news_model->get_news($slug);
            $data['news_item']=$this->news_model->get_news($slug);

            if(empty($data['news_item']))
            {
                show_404();
            }
                $data['title']= $data['news_item']['title'];

                $this->load->view('templates/header',$data);
                $this->load->view('news/view',$data);
                $this->load->view('templates/footer');
        }

$route['news/create'] = 'news/create'; $route['news/(:any)'] = 'news/view/$1'; $route['news'] = 'news'; $route['(:any)'] = 'pages/view/$1'; $route['default_controller'] = 'pages/view'; // all records upload but not issue single slug related record

it is code igniter.

please guide