ST PETERBURG, RUSSIA - APRIL 5, 2017: Flowers and candels at Spasskaya metro station in memory of the St Petersburg Metro blast victims. A blast hit a train carriage in a tunnel between Sennaya Ploshchad and Tekhnologichesky Institut stations on April 3, 2017, killing 14 and injuring more than 50 passengers. Sergei Konkov/TASS (Photo by Sergei Konkov\TASS via Getty Images)
