Alyona Kazinskaya and a friend had bought last-minute tickets to see Soviet-era rock group "Picnic's perform in front of 6,200 people at a concert hall near Moscow. They thought about taking their daughters but decided to go by themselves. At 8:01 p.m. she posted a first 10-second audio message on her Telegram channel, sounding breathless and frightened as loud bursts of gunfire rang out.