fetch same elements but different value from XML File using PHP

I want to fetch image path from bbc news XML file but there are 2 same elements media:thumbnail so when i try to fetch the image , it fetch the first element image URL and its small one .... I want to fetch the 2nd element image URL

<media:thumbnail width="66" height="49" url="http://ift.tt/1AP41rO"/>  
<media:thumbnail width="144" height="81" url="http://ift.tt/1CnZHUq"/> 

One method i have tried;

 'img' => $node->getElementsByTagName('thumbnail')->item(0)->getAttribute('url'),
 'img1' => $node->getElementsByTagName('thumbnail')->item(0)->getAttribute('url')

i declared 2 different variables and tried to fetch the URL as i thought i can use the 2nd URL but its not working thanks for helping