What we know about the chemical attack in Syria

An apparent chemical weapons attack killed dozens in Syria. More

An apparent chemical weapons attack killed dozens in Syria. The U.S. blamed the Syrian government, while witnesses and activists said the toxic substance was delivered by Syrian and Russian jets. Chief foreign affairs correspondent Margaret Warner reports and Judy Woodruff talks to Andrew Tabler of The Washington Institute for Near East Policy and Susannah Sirkin of Physicians for Human Rights.

AIR DATE 4/4/17