MASKWACIS, Alberta - Pope Francis on Monday began a long-sought act of reconciliation in Canada, decrying the country's "catastrophic" residential school system for Indigenous children and asking for forgiveness for the "evil committed by so many Christians."

"I am deeply sorry - sorry for the ways in which, regrettably, many Christians supported the colonizing mentality of the powers that oppressed the Indigenous peoples," Francis said in his native Spanish.

He addressed his comments to several thousand residential school survivors in a grass field encircled by a small grandstand on the first full day of a trip aimed at penitence for one of Canada's greatest tragedies: a school system that forcibly removed Indigenous children from their parents and tried to assimilate them into Euro-Christian society - often brutally. Students were forbidden from speaking their native languages or practicing traditional customs; many were physically or sexually abused.

"It is painful to think of how the firm soil of values, language and culture that made up the authentic identity of your peoples was eroded, and that you have continued to pay the price of this," Francis said.

His use of the word "sorry" twice drew cheers and applause. He briefly donned a feathered headdress that was given to him after his remarks, drawing louder cheers.

Francis's visit is a response to years of Indigenous requests for an acknowledgment from the Catholic Church, which ran a majority of the schools in the 19th and 20th centuries. Though Francis for much of his pontificate had demurred, he faced mounting pressure after Indigenous groups last year said ground-penetrating radar had located hundreds of unmarked graves near former residential schools.

The trip represents a major break from the norms of papal overseas travel, for which celebration and evangelization tend to be the central goals. Francis, 85, opted for only a modest welcome ceremony when landing Sunday in Edmonton, where he was greeted with Indigenous music. He chose not to issue any remarks until he arrived Monday morning in Maskwacis, an Indigenous community surrounded by yellow canola fields in the Alberta prairie between Edmonton and Calgary. The speaker who introduced him said, "Welcome to our land."

Earlier, Francis - in his wheelchair - prayed at cemetery grounds believed to hold the remains of residential school students, and he visited the former site of the Ermineskin residential school, which opened in 1895 and was operated by Roman Catholic missionaries for much of its existence. It was taken under federal control in 1969; the dormitories were closed in 1970.

Francis hosted an Indigenous delegation at the Vatican in April and apologized then for the "deplorable conduct" of some "members" of the Catholic Church in the residential school system.

Some survivors said at the time that those words did not go far enough. They hoped Francis would address the complicity of the Catholic Church. But Francis's remarks Monday hit much the same note as the earlier apology, in that he lamented the actions of individuals in the church - not the church itself.

"I ask forgiveness, in particular, for the ways in which many members of the church and of religious communities cooperated, not least through their indifference, in projects of cultural destruction and forced assimilation promoted by the governments of that time, which culminated in the system of residential schools," Francis said.

When the Presbyterian Church of Canada apologized in 1994, the actions of wrongdoing were ascribed to the church itself. "We confess that The Presbyterian Church in Canada presumed to know better than Aboriginal peoples what was needed for life," the church said in a statement at the time.

Helen Charlie, 63, a residential school survivor who flew in for the event from Whitehorse, Yukon, said that though pope didn't apologize for the broader church, he did apologize in personal terms that she found moving. "It was like he took the blame for everything," she said after the event as she moved toward the stage, hoping to meet him. She said she wanted to touch the pope's shirt, take him close and ask him to pray for the many people she knew who died young - including from alcoholism that she attributed in part to residential school experiences.

"I cried while he talked," Charlie said.

Many in the crowd wore orange shirts with the phrase "Every child matters," which are also worn to mark the National Day for Truth and Reconciliation and to remember the legacy of residential schools. People carried a 164-foot red memorial cloth with the names of the 4,120 Indigenous children who died or went missing at residential schools.

For Indigenous listeners, the event touched off a reflection that quickly moved beyond the apology to concerns about Indigenous relations with the Canadian government and what might happen next - in 50 years, in 500 years. It made many think of their fragile communities, about addiction and suicide and other aspects of trauma, and how many people who had been desperate for an apology never got to hear one.

"About 80% of my classmates are in their graves," said Chief Randy Ermineskin of the Ermineskin Cree Nation.

"Part of me is rejoiced. Part of me is sad," said Evelyn Korkmaz, a residential school survivor. "But I'm glad I lived long enough to have witnessed this apology."

The last residential schools closed in the 1990s, but the colonialist ideas that underpinned the school system continue to provoke a reckoning in the Roman Catholic Church. Francis, the first South American pope, comes from a continent where Christianity was introduced by conquerors. During a 2015 trip to Bolivia, he apologized for the church's "grave sins" during colonialism and for crimes committed against native people.

Francis has offered apologies at several points in his pontificate - most notably, before Monday, for sexual abuse in the church. His most personal apology was in a 2018 letter to Chilean bishops, in which he acknowledged what he said were his own "serious errors" in handling a sex abuse scandal. In Ireland that year, after a national reckoning over widespread clerical abuse, he asked for forgiveness for "abuse of power, the abuse of conscience and sexual abuse on the part of representatives of the church."

The Ermineskin residential school, when it operated, was one of the largest in Canada. In testimony before the country's Truth and Reconciliation Commission on residential schools, former Ermineskin students described days marked by loneliness, fear and abuse. One said she was told that the Sun Dance, an Indigenous ceremony, amounted to devil worship.

Marilyn Buffalo told the commission that teachers called the children "savage."

Overcrowding and outbreaks of diseases, including measles, hepatitis and diphtheria, were common. A 1940s survey found that one-third of the students had tuberculosis and suggested students be sent to the hospital. Instead, some were sent home and others were kept under observation.

In 1966, a supervisor at Ermineskin wrote to the chief superintendent of education at the federal Department of Indian Affairs to report that priests were whipping girls with straps on their "bare bottoms." She included the testimony of two students. She was dismissed.

At least 15 children died or went missing at the Ermineskin school during its operation, according to the National Center for Truth and Reconciliation.

Victor Buffalo was 7 years old and spoke no English when he was sent to Ermineskin. Buffalo, who is a cousin of Marilyn Buffalo, told The Washington Post that school administrators withheld food as punishment and whipped him frequently for speaking his native Cree.

After one such beating in front of his friends, Buffalo, who later became a chief of the Samson Cree Nation in Alberta, retreated to a nearby bathroom to cry - not because he was in physical pain, he said, but because his mother and father weren't there to care for him.

Buffalo said his relationship with his parents, who also attended residential schools, was strained for many decades after he left the school in 1961. Severing ties to Indigenous culture, including familial ones, was an aim of the system.

"The greatest thing that we lost was love," Buffalo said ahead of Francis's visit. "The love of a family, the love of a mother, the love of a father."

As the grounds cleared out after the pope departed, some played music and chatted. Cecilia Saddleback, 78, sat on a chair and tried to reflect. She said the painful memories the day dredged up left her with "mixed feelings."

"The nuns [at the residential school] used to talk down to us," Saddleback said. "They'd say, 'You're not going to amount to anything.' "

But then Saddleback thought again. She'd become a teacher. The nuns were wrong, it had turned out. And now the pope had come to visit her.

"I don't have to spend money to go to Rome," she said.