Не выводит записи PHP MVC

Только изучаю MVC. Не могу понять в чем проблема.

Модель

<?php

class IndexModel extends Model {

    public static function loadDepartment(){

        $sql = "SELECT * from department";
        $stmt = db::connToDB()->query($sql); 
        $stmt->fetch(PDO::FETCH_ASSOC);
        $mass = array();

        $i=1;
        while($row=$stmt->fetch()) {

            $mass[$i] = $row['departmentName'];
        
            $i++;
            
        
        }
        return $mass;

    }
    
}

Контроллер

    <?php

class IndexController extends Controller {

    private $pageTpl = '/views/main.tpl.php';


    public function __construct() {
        $this->model = new IndexModel();
        $this->view = new View();


    }


    public function index() {
        $this->pageData['title'] = "Вход в личный кабинет";
        $this->view->render($this->pageTpl, $this->pageData);
        $departmentList = array();
        $departmentList = IndexModel ::loadDepartment();
        require_once("view/main.tpl.php"); 
    }


}

Вью

<?php foreach($departmentList as $key) { ?>
    <option><?php print $key["departmentName"]?></option>