Russian President Putin has vowed to punish those responsible for the terror attack on a suburban Moscow concert hall that killed at least 133 people. In the capital, people are remembering the dead after one of the worst acts of terror in Russia in decades. Journalist Michael Weiss joins John Yang to discuss the Islamic State branch that claimed responsibility for the attack and Putin’s response. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok: https://www.tiktok.com/@pbsnews Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe