PHILADELPHIA — Pope Francis joined hundreds of thousands of the faithful Sunday for the last and biggest event of his joyful, six-day U.S. visit — a Mass on Philadelphia's grandest boulevard — after meeting with victims of the church sex abuse scandal and offering words of hope to jail inmates.
Riding through the streets in his open-sided popemobile, the pontiff waved to cheering, screaming, singing, flag-waving crowds as he made his way up the Benjamin Franklin Parkway and reached the altar at the foot of the broad steps of the Philadelphia Museum of Art.
It was the final stop on his itinerary before the 78-year-old pontiff was to return to Rome.
Organizers predicted a crowd of 1 million, though there were fears that the unprecedented security, including airport-style bag searches, crowd-control cattle chutes and blocked-off streets, had scared many people away and would depress the turnout.
En route to the Mass, Francis stepped off his popemobile to see an art installation with particular meaning for him: Inside the grotto outside Philadelphia's cathedral were 30,000 white knotted ribbons, each representing a personal hardship or societal challenge.
The exhibit was inspired by one of Francis' favorite paintings, "Mary, Undoer of Knots," showing Mary untangling a long ribbon symbolizing life's difficulties. The painting hangs in a church in Germany, where then-Rev. Jorge Mario Bergoglio saw it while studying in the mid-1980s.
Earlier in the day, in a gesture of reconciliation, he met with victims of child sexual abuse and told them he is "deeply sorry" for the times they came forward to tell their story and weren't believed. He assured them that he believes them and that bishops will be called to account for what they did.
"I pledge to you that we will follow the path of truth wherever it may lead," Francis said in Spanish. "Clergy and bishops will be held accountable when they abuse or fail to protect children."
Then, he went into a meeting with American bishops in town for a Catholic festival on the family and told them the same thing face-to-face.
"God weeps" over what was done to the youngsters, he said.
Also, Sunday, Francis visited a Philadelphia jail to give hope of redemption to about 100 inmates, included suspected killers, rapists and mobsters. He greeted the men one by one, telling them to use their time behind bars to get their lives back on track.
"May you make possible new opportunities, new journeys, new paths," he said, standing before a wooden chair the men had made for him for the occasion.
The blue-uniformed inmates, some of them heavily tattooed, seemed moved. They clasped Francis' hands, and two gave him a hug.
Francis' journey also took him to Washington and New York. Along the way, he drew large and adoring crowds, met with President Barack Obama, visited ground zero and addressed Congress and the United Nations, calling for urgent action on climate change and poverty.
As the hour of the papal Mass in Philadelphia approached, people endured hourslong waits to pass through security checkpoints, and the lines stretched for several blocks.
Sarah and Terrence Williams, both 36, of Williamstown, New Jersey, have been trying for more than a year to have a baby and said they were hoping that attending the Mass might result in a miracle.
"Hopefully he'll drive by and just his acknowledgment will be the blessing we need to get our miracle," Terrence Williams said.
Thomas Coorey, a dentist and father of four visiting Philadelphia from Sydney, called Francis "the most inspirational and amazing pope that could breathe life into this church of mine."
The meeting on Sunday with victims of sexual abuse was the second one Francis has held. He received some at the Vatican in July 2014.
But in an apparent effort by the church to reshape the discussion, the Vatican said not all five of the victims on Sunday were abused by members of the clergy; some of the three women and two men had been victimized by relatives or educators.
Victim support groups were unimpressed by the meeting.
The main victims' support group, SNAP, dismissed it as an exercise in public relations.
"Is a child anywhere on Earth safer now that a pope, for maybe the seventh or eighth time or ninth time, has briefly chatted with abuse victims? No," said SNAP's David Clohessy.
The Rev. Tom Doyle, a canon lawyer who worked at the Vatican embassy in Washington and is now an advocate for victims, said that including more than just victims of abusive clergy "seriously minimizes" the problem in the church.
"We don't think we're going to get any real support to change this from the leadership in the Vatican," Doyle said. "They're having this big meeting of families. But there's been no real room for all the families that the Catholic Church has destroyed through sexual abuse."
The Archdiocese of Philadelphia has been hit hard by the scandal and has been the subject of repeated grand jury investigations, including one that accused it of keeping on more than three dozen priests facing serious accusations. A monsignor was found guilty of endangering children by not removing pedophile priests, becoming the first American church official convicted of such an offense.
The pope has agreed to create a new Vatican tribunal to prosecute bishops who failed to protect their flock, and he has accepted the resignations of three U.S. bishops accused of mishandling cases. During the previous meeting with victims, he similarly vowed to hold bishops accountable.
At the same time, Francis and U.S. bishops have also argued that child molestation is a serious problem beyond the church, especially within families and in schools. The meeting with victims abused by people other than priests underscored that point.
The Vatican spokesman, the Rev. Federico Lombardi, said the pope met with the victims for more than a half-hour at the St. Charles Borromeo seminary. He said the pope prayed with them and listened to their stories.
During the meeting with the bishops, Francis referred to gay marriage for the first time in his U.S. trip, lamenting the new reality in which Christians must live.
But he also urged the bishops to redirect their energy away from complaining about it, saying a church that does nothing but explain its doctrine is "dangerously unbalanced" and "stuck in a vicious circle."
The U.S. bishops have spent considerable time and resources battling gay marriage, calling its legalization by the U.S. Supreme Court three months ago "a tragic error" and "profoundly immoral and unjust."
Associated Press writers Michael R. Sisak, Maryclaire Dale and Kathy Matheson contributed to this report.
This story has been corrected to show that the seminary is named St. Charles Borromeo, not San Carlo Borromeo.