A former president of Israel's Supreme Court was appointed on Sunday to head its state commission of inquiry into a stampede at a Jewish pilgrimage site in April that killed 45 people, among them U.S. and Canadian citizens.

Tens of thousands of ultra-Orthodox Jews thronged to the Galilee hillside tomb of 2nd-century sage Rabbi Shimon Bar Yochai on April 30 for the annual Lag B'Omer festival that includes all-night prayer, mystical songs and dance.

During the ceremony, part of the crowd surged into a narrow tunnel and 45 men and boys were asphyxiated or trampled to death. Israeli media said at least six of the fatalities had U.S. citizenship and two had Canadian citizenship.

Ordering the inquiry last week, Prime Minister Naftali Bennett said it would help safeguard other mass-attendance events in Israel, which has sites sacred to Christianity and Islam as well as to Judaism.