Syria's white helmets are the country's first responders. They're there when bombs go off, when buildings collapse, when bodies need to be recovered and the wounded hospitalized. "Last Men in Aleppo," a documentary directed by Syrian filmmaker Feras Fayyad in collaboration with the Aleppo Media Center, follows two men from the White Helmets who navigate the war-torn city of Aleppo in various search-and-rescue missions.