Greenblatt: 'Heartbroken' about news of Chabad of Poway attack

US Middle East Envoy Jason Greenblatt tweeted, "Checked the news tonight after celebrating Passover; heartbroken to discover the horrible news about the deadly attack at a synagogue in Poway. We must gather together & fight the scourge of anti-Semitism. My thoughts & prayers are with the families of all those affected."