Reports of a new chemical attack in Syria

New reports out of Syria of a chemical attack that may have already claimed hundreds of lives. The Assad regime denies it, but new video appears to show the victims. CNN cannot immediately verify the legitimacy of the video, but the U.N. says it will try to investigate. CNN's Arwa Damon has the latest on a very dangerous situation.

For more context on the latest fighting in Syria, check out tonight's AC360 411