American aid worker and former U.S. soldier Peter Kassig has been beheaded by ISIS terrorists. Kassig first went to the Middle East after he joined the U.S. Army in 2006.
He was briefly deployed to Iraq a year later.
But he returned in 2012 on his own, to deliver humanitarian aid to Syrians affected by the fighting there.
In an interview with CNN's Erin Burnett, Sarah Pollom, a friend of Kassig's, says his mission in life was to make a difference.