Poland mulls activating NATO Article 4 after 'Russian-made' missile blast

The world is alarmed after alleged Russia-made missile landed in NATO member country Poland's territory. Two people were killed when the projectile struck the village of Przewodów, which is near the Ukrainian border. Polish President Andrzej Duda said in a tweet that he spoke with NATO Secretary General Jens Stoltenberg and verified 'the premises of Article 4.' Watch this video to find out what Article 4 of NATO states.