Residents in several cities and towns across Serbia blocked traffic and stood in silence for 15 minutes on Friday to commemorate the 15 victims of a roof collapse in the country’s north three weeks ago.

In Serbia, twelve individuals face charges related to a deadly roof collapse at Novi Sad train station, which killed 15. The arrests were made after public outrage over alleged corruption and irregular construction practices.

The collapse in Novi Sad has triggered a wave of protests against the populist authorities and arrests of several activists who have taken part. Many in Serbia believe rampant corruption led to sloppy renovation work at the station and consequently to the roof collapse.