MASKWACIS, Alberta (AP) — Pope Francis issued a historic apology Monday for the Catholic Church’s cooperation with Canada’s “catastrophic” policy of Indigenous residential schools, saying the forced assimilation of Native peoples into Christian society destroyed their cultures, severed families and marginalized generations in ways still being felt today.

“I am sorry,” Francis said, to applause from school survivors and Indigenous community members gathered at a former residential school south of Edmonton, Alberta, the first event of Francis’ weeklong “penitential pilgrimag...