After retiring from professional life, Fischer continued to provide free medical care to local residents.
He was residing with his Palestinian wife in Beit Jala near Bethlehem when his village was attacked by Israeli helicopter gunships.
Fischer initially took cover under a stairwell with his wife, but later left his home to assist an injured neighbor whose house had been partially destroyed in the attack.
As he entered the street Fischer was struck and instantly killed by an Israeli missile that left one of his legs severed and his body riddled with shrapnel.
Fischer's 17-year-old son Danial recounting his father's death in an interview with the Chicago Tribune said "Sometime during the night we heard our neighbors, the Assaf family, cry out for help," he recalled "Their house was hit and on fire.