Putin Declares Day of Mourning After Concert Hall Terror Attack

Russia observed a day of mourning Sunday, two days after a deadly attack at a suburban Moscow concert hall that killed more than 137 people, including three children, and injured over 180.

Rescue teams continue to scour the scorched building for survivors as some families still agonize over the fate of their loved ones. Hundreds of people stood in line in Moscow to donate blood and plasma, Russia's health ministr