Angela Merkel, Germany's chancellor, second left, holds a white rose while looking at floral tributes with Michael Mueller, Berlin's mayor, left, Thomas de Maiziere, Germany's interior minister, third left, Frank-Walter Steinmeier, Germany's foreign minister, second right and Andreas Geisel, Berlin's interior minister, near the scene of yesterday's terror attack, in Berlin, Germany, on Tuesday, Dec. 20, 2016. Merkel said that German authorities were working on the assumption that the deaths of 12 people after a truck rammed a Berlin Christmas market were a terrorist attack. Photographer: Jasper Juinen/Bloomberg via Getty Images