U.S. in Iraq | PBS NewsHour Weekend | New airstrikes target Islamic State fighters holding dam

Airstrikes hit positions near a key dam in northern Iraq, which had been recently captured by Islamic extremists, a day after the extremists — members of the Islamic State — are said to have massacred dozens of Yazidis. Liz Sly of The Washington Post joins Hari Sreenivasan via Skype from Iraq.