As Russia mourns concert hall attack, some families are wondering if their loved ones are alive [Video]

Family and friends of those still missing after an attack that killed more than 130 people at a suburban Moscow concert hall waited for news of their loved ones as Russia observed a day of national mourning on Sunday.Video above: Hundreds queue to donate blood after deadly concert hall attack in MoscowEvents at cultural institutions were canceled, flags were lowered to half-staff and television entertainment and advertising were suspended, according to state news agency RIA Novosti. A steady stream of people brought flowers to a makeshift memorial near the burnt-out concert hall.”People came to a concert, some people came to relax with their families, and any one of us could have been in that situation. And I want to express my condolences to all the families that were affected here and I want to pay tribute to these people,” Andrey Kondakov, one of the mourners who came to lay flowers …