Ambulances are seen outside the main building of Kazan airport Nov 17, 2013. A Boeing 737-500 airliner crashed on landing in the Russian city of Kazan on Sunday, killing all 50 on board and highlighting the poor safety record of Russian airlines that ply internal routes across the world's largest nation. The Tatarstan airlines flight from Moscow was trying to abort its landing in order to make a second approach, but it exploded on hitting the runway, killing all 44 passengers and six crew on board, emergency officials said. [Photo/Agencies]