Getting Column Numbers with Actual Column Names in PHP/MySQL

Here is my query:

$query = "SELECT last_name, first_name, DOB, site, COUNT(*) AS Num FROM student "
    . "WHERE site = '{$siteRow['site']}' "
    . "GROUP BY last_name, first_name, DOB having Num > 1";

When I run this on a MySQL client, I get the appropriate rows. last_name, first_name, DOB, site, and Num

However, when I try to do this (and testing with a var_dump) thru php, I get those same five col;umns, but before each one, I get 0,1,2,3, and 4 - each one corresponding with the 5 columns above in the order written.

Here is php:

$result = $DB->query($query);
$cnt = $DB->count($result);
if ($cnt > 0) {
            while ($row = $DB->fetch_array($result)) { // solved; issue here!
                    if (!in_array(strtolower(trim($row['site'])), $dup_student_sites)) {
                    $records[] = $row;  
                    $dup_student_sites[] = strtolower(trim($row['site']));
                    $dupCount++;
                }

            }
        }


var_dump($records);  // tested here to see result with row numbers

Here is the output of the var_dump (partial):

array(111) {
  [0] =>
  array(10) {
    [0] =>
    string(7) "---"
    's_s_last_name' =>
    string(7) "---"
    [1] =>
    string(4) "---"
    's_s_first_name' =>
    string(4) "---"
    [2] =>
    string(10) "2003-03-20"
    's_s_DOB' =>
    string(10) "2003-03-20"
    [3] =>
    string(8) "---"
    's_s_site' =>
    string(8) "---"
    [4] =>
    string(1) "2"
    'Num' =>
    string(1) "2"
  }