He wasn't a fighter or a revolutionary, he didn't live by the gun. But 45-year-old Hassan, a shopkeeper, died from an unseen sniper's bullet.

Neighbors and fighters had to hoist his body over walls between apartment buildings in the back streets of Aleppo's Mashhad neighborhood to avoid the snipers.

His wife was by his side when the bullet ripped through his head. The couple had come here to help relatives pinned down by the violence to escape to safer ground.

The line between life and death is perilously thin in Aleppo, Syria's largest city and the focus of fighting between government and rebel forces that have been seeking the overthrow of President Bashar al-Assad.