The Roman Catholic Church in Los Angeles has apologised to hundreds of people abused by priests after agreeing to a record-breaking settlement.
Cardinal Mahony described the abuse as a "terrible sin and crime"
The apology by Cardinal Roger Mahony, the Church's leader, comes after the 508 victims reached a pay-out deal with the church worth $660m (£324m).
A Los Angeles judge approved the deal, saying it was "the right thing to do".
The deal was reached just before a series of trials into sex claims dating back to the 1940s was to begin.
"I have come to understand far more deeply than I ever could the impact of this terrible sin and crime that has affected their lives," Cardinal Mahony told a news conference.
"There really is no way to go back and give them that innocence that was taken from them. The one thing I wish I could give the victims... I cannot.
"Once again, I apologise to anyone who has been offended, who has been abused... It should not have happened and should not ever happen again."
The agreement settles all 15 paedophilia cases against the Los Angeles archdiocese and avoids the threat of Cardinal Mahony being forced to testify about how the Church dealt with abuses spanning the 1940s to 1990s.
The Church had already settled 45 cases last December with a payment of $60m.
Since 2002 nearly 1,000 people have filed abuse claims in California
Los Angeles diocese records released in the past revealed that for decades priests accused of child sex abuse were simply moved to new assignments or provided with therapy, Church leaders believing that they could be rehabilitated.
The settlement also calls for the release of confidential priest personnel files, said Ray Boucher, the victims' main lawyer.
"Transparency is a critical part of this and of all resolutions," he said.
Steven Sanchez, a 47-year-old plaintiff in the case, said he was both relieved and disappointed by the outcome.
"I was really emotionally ready to take on the archdiocese in court in less than 48 hours, but I'm glad all victims are going to be compensated," he said.
Another victim, Lee Bashforth, spoke outside court holding a photograph of himself as a seven-year-old boy with the priest he says abused him.
He described Cardinal Mahony's apology as "disingenuous and hollow", saying the Church had only settled in order to avoid answering questions in court.
The $660m-deal dwarfs the $157m settlement paid out by the diocese of Boston following a child sex scandal which became public in 2002.
Plaintiff Steven Sanchez had been preparing for trial
The Los Angeles payment, which amounts to an average of $1.3m for each plaintiff, takes the total paid out by US dioceses to $2bn since 1950, with Los Angeles paying about one quarter of that.
Los Angeles is the country's most populous Catholic diocese, serving more than three million parishioners, but the scandal has brought the archdiocese close to financial ruin.
According to Church lawyers the diocese is likely to pay $250m in cash, the rest of the sum being covered by insurance and payments by religious orders.
Earlier this year, Cardinal Mahoney told parishioners in an open letter that the Church would sell its 12-storey administrative building and was considering the sale of about 50 other non-essential properties to raise funds.
David Clohessy, national director of the Survivors Network of those Abused by Priests, said while it was the largest settlement by the Church, money was not the key objective for victims.
"No settlement, no amount of money, can restore the shattered trust and the stolen childhoods and the betrayed faith of people who were wounded by abusive priests and by complicit bishops," he said.
"But, having said that, certainly this represents a tremendous achievement by these brave survivors, who somehow found the strength to come forward, report the crimes, get legal help, expose the predators and ultimately endure a pretty long, gruelling legal process."
Since 2002 nearly 1,000 people have filed such claims against the Roman Catholic Church in California alone.
In February 2004, a report commissioned by the Church said more than 4,000 Roman Catholic priests in the US had faced sexual abuse allegations in the last 50 years.