Iraqi forces close in on Mosul, ISIS's de facto capital

The Iraqi army is moving closer to taking back control of Mosul from Islamic State militants who captured the city three years ago. U.S. Army forces are joining Iraqi troops in the fight while thousands of civilians, trapped in the conflict, attempt to flee. Stephen Kalin, a Reuters reporter covering the conflict, joins Hari Sreenivasan via Skype from Irbil, 60 miles from Mosul.