By Nick Bryant In Boston

"For Boston Catholics, this is our 11 September. It's that catastrophic." Professor Thomas Groome uses the metaphor with great caution; he means no disrespect.

But the archdiocese is "ground zero" in a paedophile priest scandal which has swept across the country.

It is a crisis which threatens not only to bankrupt the American Catholic Church, but which has completely undermined its moral authority.

A suspicion-filled divide has opened up between the priesthood and the laity. And nowhere are its consequences more deeply felt than in Boston.

'Old boys' network'

Professor Groome is one of the city's leading Catholic theologians, an adopted Bostonian, with a lilting Irish brogue. "They acted like an old boys' network", he says, an edge of exasperation creeping into his voice. "They didn't think about the children."

Fears of protest forced Cardinal Law to cancel his weekly mass

The central allegation against the Catholic hierarchy here is damning: that it knew of paedophile priests who were suspected of sexually abusing children for decades, but simply moved them from parish to parish when the victims complained.

A wealth of documentary evidence points to an evil conspiracy - and speaks of a stunning fall from grace.

When the framers of the American constitution codified the separation of church and state - nobody thought to tell Boston, a blue-collar city where the Catholic Church is dominant.

Priests here are like tribal chieftains, wielding enormous political power.

Cardinal Richard Cushing, its leader in the 1950s, once claimed that he'd plotted how John F Kennedy would become president.

And until recently, the endorsement of a local priest could swing city hall elections.

Protests

Now though, the church is in disgrace - its present leader, Cardinal Bernard Law forced last Sunday to cancel his weekly mass out of fear that protesters would disrupt it.

Cardinal Law was once tipped to become the first American pope. Now he is shying away from his congregation - a prisoner in his multi-million dollar mansion.

Cardinal Law is under fierce pressure to resign. He admits that the church knew that a Boston priest sent to prison earlier this year was suspected of being a serial child molester - but did little to protect children in his care.

Father John Geoghan is thought to have sexually abused more than 130 children over a 30-year period. In the Boston Archdiocese alone up to 100 priests now face similar allegations.

The scandal has been given a passionate new intensity by the most recent revelations.

'Living hell'

They concern a priest called Father Paul Shanley, who is alleged not only to have molested young children but publicly advocated sex between men and boys.

Even after the church had paid financial compensation to several of his victims, Mr Shanley was allowed to remain as a priest.

When I grew up as a Catholic they taught you the difference between heaven and hell, and you got there when you died. Well they're wrong, we got to hell when we were living

Rodney Ford

Cardinal Law even wrote a glowing reference when he applied to run a hostel in New York, whose guests included teenagers.

It is no wonder that, victims express bitterness and dismay.

Take Rodney Ford, barrel-chested and apple-cheeked, every inch the proud Irish-Catholic Bostonian.

His son, Greg, was allegedly molested by Shanley over a period of 10 years. "When I grew up as a Catholic", he says, "they taught you the difference between heaven and hell, and you got there when you died."

"Well they're wrong," he adds, his voice bristling with anger. "We got to hell when we were living".

Zero tolerance

Without question there is a crisis of confidence in the Catholic Church here right now, with the priesthood and laity questioning age-old articles of faith.

Should priests remain celibate? Should they be allowed to marry? Could there even be a break with Rome if the Vatican fails to come up with an adequate response?

The church in Boston has reacted by announcing a policy of zero tolerance, referring allegations against priests to civil authorities.

But for decades there's been a policy of zero compassion - the church more interested in protecting its image than safeguarding children in its care.