The story of the young girl who was tortured and repeatedly raped by her father and is now homeless has shocked the nation. But she is one among many. This girl's experience has been particularly horrendous, but there are hundreds of children in Ireland in situations broadly similar. They have all had to leave home because of some sort of problem there, often because of violence and abuse, and they are all at risk.

Homelessness among children is a relatively new phenomenon. When Focus Ireland started in 1985 there were no homeless children and only a small number of teenagers out-of-home in Dublin. But the numbers have increased each year and the age profile of homeless children has become younger. By 1990 there were 300 children and young people homeless in Dublin, and each year these figures continue to increase.

Homeless children fall into two categories. There are those who are part of homeless families, and that is a separate problem; and there are children, like this girl, who are theoretically not homeless - in the sense that they have homes of some sort, somewhere - but are homeless in practice, because they cannot return to those homes.

It is one thing, and bad enough, to be unable to live at home because of neglect, abuse or violence, but it is another to have nowhere else to go. The original cause of a child's homelessness may be neglect or abuse at home, but the fact that society makes no alternative provision for them is equally a factor in their homelessness.

Nobody chooses one day to be homeless. Homelessness happens to people, and there are reasons and explanations for it. We live in a wealthy society, where one might expect that homelessness wouldn't happen, or wouldn't happen much, but behind this facade of wealth there is an invisible Ireland of the poor. Ireland has one of the highest rates of child poverty in the EU.

The number of people experiencing poverty and unemployment has fallen, certainly, with the improvement in the economy, but for those who are being left behind in poverty, the gap between them and the rest of us is widening.

They are becoming even more disadvantaged and marginalised. They live in areas of multiple deprivation, where the implementation of service planning and infrastructure is piecemeal and where unemployment runs well above the national average, sometimes as high as 70-80 per cent, and early school-leaving and social exclusion are the norm. It is no accident that children who become homeless and remain so come from these areas.

Another cause of child homelessness has been the rate of change in our way of life. Family life is breaking down and neighbourhood and community networks are loosening. In the past, if a child was unable to be cared for in his or her own family, he or she was often cared for by the extended family or within the local neighbourhood. But these supports and controls, which were there up to 15 years ago, have disappeared right before our eyes.

Children who are homeless and on the streets should be in care, but we no longer have the range of institutions to care for such children we used to have. We know today that some children suffered enormously in such institutions, but the whole system was not abusive and good-quality care and aftercare were provided to thousands of children over the years throughout the country.

From the mid-1980s, however, the religious orders began to withdraw from this work, and as they withdrew, they left a vacuum. It then fell to the State to care for children who couldn't remain in their own homes.

But the State has never been prepared to take on this responsibility, even though the religious orders made it clear to government departments they were withdrawing from childcare. The Department of Health and the health boards had no tradition of residential care and were unable to plan for the situation or put a structure in place.

The result has been the situation we see today, where children are homeless because they cannot be taken into care, and they cannot be taken into care because the provision of care is totally inadequate.

The longer it goes on, the worse the problem gets. Not only are there more and more children becoming homeless, but the situation of those children who are on the streets worsens, their problems become more complex and they become more and more difficult to care for, even if care is available.

It is almost impossible to care for children such as these unless intervention is built into the system to assist families and to prevent them leaving home in the first place, as well as assisting them from the point when they first leave home. Once they live on the streets and slip into a life of abuse, prostitution and drugs, they become less able to access the system, and the system becomes less able to help them.

What is needed to respond to these desperate circumstances is a total transformation of the system. We are badly in need of a comprehensive, coherent and cohesive national policy on, and strategy for, dealing with children at risk and children who need to be cared for outside their own home.

This requires an infrastructure of integrated child and family services that is directed to meet the needs of children and families at local, regional and national levels. There is nothing new about this demand. It was asked for by other groups and has been called for by Focus Ireland each year since 1989.

It has to be said, in fairness, that since the early 1990s various ministers, particularly Chris Flood, Frank Fahey and Mary Hanafin, have tried to improve the system by investing resources in the voluntary and statutory sectors.

More social workers have been employed and more money has been made available to voluntary bodies like Focus Ireland. But as ministers of State who took their portfolio seriously, they simply didn't have the clout to reform the system in the radical way it needs to be reformed.

The kind of radical overhaul the system needs cannot be implemented as things stand at Government level. What is required is nothing less than a full government department in the charge of a senior minister who has the power and the resources to co-ordinate reform. We need someone with full authority who can draw up a national strategy, implement a co-ordinated plan and monitor its implementation and progress.

What we have had instead has been dissipation of the responsibility for children in need of care across various Departments - Education, Family and Health, and Justice. More recently, in an attempt at co-ordination, we have had ministers of State with a brief to work across various Departments, but this gives rise to divided responsibility.

Such a fragmented set-up cannot provide the level of radical action, backed up by resources and followed up by monitoring, that is needed in a situation that has such serious consequences for children.

The inevitable outcome has been that national planning and a coherent national childcare policy are impossible to achieve or implement, and the result, in turn, is that suitable placements are often not available for children in need of care. And so the homelessness of young people is perpetuated by the very system that is supposed to be trying to prevent it.

One department under one minister is what we have been asking for - pleading for - because it is the only answer if we are to have a coherent policy, plan, practice, system and structure for children in need of care and their families.

No matter how hard social workers, childcare workers and voluntary organisations work on the ground, they cannot put in place what is needed until the Government puts in place a department for children with a minister who has a clear brief and a clear portfolio.

If this doesn't happen the situation will continue to worsen and we will continue to have child after child appearing before the courts because the State has failed to take on its responsibility in relation to children in need of care.

We will continue to have distressing cases of tortured children homeless and on the streets coming to the attention of the media. We will continue to move from one disaster to another until the Government takes on its responsibility.

The Minister for Health, Micheal Martin, announced this week the appointment of a director of services for homeless people within the recently established Eastern Regional Health Authority, but that is not the answer.

A director working for the ERHA simply cannot have the authority needed, authority at Government level. Multidisciplinary teams working on the ground with young people who are victims of our society, admirable though it is as a concept, is not the answer either. Nor is giving resources to voluntary agencies. Each of these measures can only be effective in the context of a department for children with a government minister in charge.

Last year the Taoiseach expressed his shock at the way in which the abuse of children in care in the past had damaged so many lives. He apologised for "our collective failure to intervene, to detect their pain, to come to the rescue".

It is right that the dreadful failures of the past should be acknowledged and that the victims should be compensated in every possible way, and I know that the Taoiseach will ensure that the State does compensate them for the State's neglect in the past.

But it is one thing to apologise for the failures of the past; it is a much more difficult thing to intervene now, to detect the pain of today's children and to come to their rescue. We all ask about the past: how was it allowed to happen? Why didn't somebody do something?

Well, now we have the opportunity to do something about a new situation of pain and abuse for children, but unless the Government grasps the situation and puts in place the measures we are calling for, we will continue daily to fail our children at risk, as people in the past failed those children who were abused in care.

Will the Taoiseach, who is so distressed about the abuses of the past, now take a leading role in putting in place a system that will ensure that never again will a child in need of care be neglected or abused? Will he, for the love of God, institute a department for children and appoint a senior minister with full authority to head it?

Sister Stanislaus Kennedy is president of Focus Ireland