NOVI SAD, Serbia — Serbia's students led a mass street protest and began blockading three bridges over the River Danube 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.

Serbia’s students will lead mass demonstrations and blockades of three bridges over the Danube river in the northern city of Novi Sad to mark three months since a concrete canopy crashed down at a train station there,