Sam was a survivor along with his older brother Henry in The Last of Us. The outbreak occured when Henry was only a child in Hartford, while Sam was born seven years afterwards. After the military abandoned the quarantine zone in Hartford, Sam along with a group of survivors headed for Pittsburg, where they were attacked by Hunters.
While hiding from the Hunters in Pittsburg the brothers run into Joel and Ellie. The four wait for nightfall to escape the city full of Hunters and infected, but Sam becomes infected. Hiding the information from the group leads to Ellie being attacked the next morning. Blaming Joel, Henry if forced to shoot his brother and then kills himself.
