An aerial view of people hold up their mobile phone lights during a protest in front of a railway station where the collapse of a concrete canopy killed 15 people more than two months ago, in Novi Sad, Serbia, Friday, Jan. 31, 2025. (AP Photo/Armin Durgut) NOVI SAD – Serbia's students will lead mass demonstrations and blockades of three bridges over the Danube river in the northern city of Novi Sad on Saturday to mark three months since a concrete canopy crashed down at a train station there, killing 15 people. The collapse on Nov. 1 of the huge concrete…