HARI SREENIVASAN:

The six-week-long battle for the ISIS-held city of Mosul has become an increasingly tough urban war for the American-backed Iraqi forces. Up to a million civilians still live in the city.

The front lines are often too dangerous for international aid workers, but two young American volunteers are there saving lives while risking their own.

From Mosul, special correspondent Jane Ferguson and producer Matt McGarry filed this report.