Al Qaeda leader Ayman al-Zawahiri killed by U.S. drone strike in Afghanistan
A U.S. drone strike has killed Ayman al-Zawahiri, an al Qaeda leader suspected of helping plan the 9/11 attacks. He was Osama Bin Laden's deputy for more than a decade, becoming the terror group's leader after Bin Laden was killed by Navy SEALs in 2011. CBS senior investigating correspondent Catherine Herridge reports.