During the Battle of Bint Jbeil, a hand grenade was thrown into the house where Klein and his unit were present. Klein told his men "Report that I've been killed" and subsequently jumped on the live grenade and stopped the explosion with his body . The soldiers reported that Klein recited the Jewish prayer, Shema Yisrael, as he jumped on the grenade .
Roi Klein became a symbol for heroism in Israel. New schools in Netanya and Raanana have been named after him.
For his actions during the war Klein received the Medal of Valor posthumously.