http://worldnews.nbcnews.com/_news/2013/12/30/22103858-rush-hour-blast-kills-14-on-trolley-bus-in-volgograd-russia-3rd-deadly-attack-in-four-days?lite http://www.reuters.com/article/2013/12/30/us-russia-blast-trolley-idUSBRE9BT03N20131230