Iranian President Ebrahim Raisi and Foreign Minister Hossein Amir-Abdollahian have been confirmed dead after their helicopter crashed on Sunday. Iranian government has called this an accident, contributing the tragedy to bad weather conditions and a technical failure. The crash occurred at a time of rising tensions in the Middle East. What more do we know about the accident? How will Iran fill the power vacuum? And how might this influence Iran's domestic and international policies as well as its involvement in the region? To take a closer look, we are joined by Professor Seyed Mohammad Marandi and Professor Foad Izadi from the University of Tehran; Professor Wang Jin from Northwest University of China；and Professor John Ghazvinian, executive director of the Middle East Center at University of Pennsylvania.