CNN  —  On the first day of November, Aleksandar Matkovic was running late for a train. He was traveling from Novi Sad, in the north of Serbia, to its capital Belgrade, where he works as an economic historian. When he got to the station, he witnessed a scene of horror that has rocked the country to this day. Minutes before he arrived, the canopy of the station – where reconstruction had been completed months earlier – had collapsed, crushing passengers waiting on the platform. Fifteen people