Taliban's Killing of Top Negotiator a 'Clear Signal'...

Aired: 9/20/2011 | 0:05:14 | Clip
Burhanuddin Rabbani, a former Afghan president in charge of negotiating with the Taliban, was killed Tuesday by a suicide bomber posing as a peace envoy. Margaret Warner gets the latest details, reactions and information on the suspected perpetrators from Patrick Quinn of The Associated Press, speaking from Kabul.