Losing family is heartbreaking, the pain all the more acute in sudden events such as accidents and disasters. Many well-wishers rally round in the immediate aftermath to offer help and comfort, but people often take time to work through their grief. Experts say survivors and families of victims in tragedies such as the Indian Ocean tsunami and Monday's hostage debacle may find the going hardest well after the initial wave of attention and sympathy has abated.

Fortunately for Tong and her sister, good support networks helped see them through the process and the impact of their personal loss has eased over the years. 'We do understand that [what happened] is in the past,' she says.

It helps that both are engaged in work they can derive comfort from: Tong is a social worker and her sister is a full-time church volunteer.

Grieving people generally go through several stages - first feeling denial and anger, then abandonment, depression and finally acceptance, says Helios Lau Kar-cho, chief clinical psychologist of the Social Welfare Department.

Helping the bereaved resume normal, functioning lives goes a long way towards speeding up the healing process. But each person copes differently and some may be caught up in feelings of denial or anger for an extended period, Lau says.

Others suffer moods swings or are unable to form relationships. They must learn to accept the loss to avoid being incapacitated by unresolved emotions. Professional help may be needed.

In cases of 'man-made' tragedies such as Monday's hostage killings, Lau says, individuals may be caught in the 'anger' stage, especially if they witnessed the event.

Some can struggle with very negative, destructive impulses, says Cecilia Chan Lai-wan, a professor of social work at University of Hong Kong. Recalling how she counselled a man whose wife died in a fire, she says he carried a strong grudge for years. He felt that the world was unfair and saw disasters or other people's misfortune as balancing events.

Kitty Wu Kit-ying, convenor of the Hong Kong Psychological Society's critical incident team, says people suffering traumatic grief may become hypersensitive or think they see lost family members when they catch glimpses of people who resemble them.'Some will avoid seeing people - including their loved ones and relatives - and any mention of the [trauma].'

But such avoidance will impair their recovery because emotional support is a very important element in the process, Wu says.

It helps to get back to work or school as soon as possible to restore some normality to their lives. Relatives and friends play an important role in healing but need to be very sensitive, Lau says.

Some individuals require more privacy so permission should be sought before talking about their loss. Friends and family should try to help in practical ways and simply give the bereaved the chance to talk.

People who live through traumatic events may face other issues such as so-called survivor's guilt - feeling they bear some sort of blame for having lived or emerged unscathed when others were killed and hurt, or because they were unable to save the rest.

One way of countering survivor guilt is to encourage them to engage in productive activity such as helping others, says Chan, who has led a number of initiatives to counsel and assist survivors of the Sichuan earthquake over the past two years.

Conducting rituals such as remembrance or celebration-of-life gatherings can help mourners. They might name a dish or use expressive art to commemorate the life of a loved one, for example.

Joining mutual support groups with others who have experienced similar traumas and getting involved in advocacy work may also be helpful in the grieving process, Chan says.

Tong can attest to that. After the tsunami, she and two colleagues set up a volunteer group, Hands in Hands, to provide counselling and practical help for Hong Kong survivors and victims' families.

It felt good 'being able to help others in a concrete way', Tong says.

The group enabled families to give each other moral support by sharing their struggles with daily life, says Cheung Kwok-che, president of the Hong Kong Social Workers' General Union.

The volunteers also organised anniversary Christmas gatherings to honour victims of the tragedy, and some are still in contact with the families. But children caught in such devastating events may find it particularly hard to cope and the young survivors of Monday's hostage tragedy could face tough years ahead.

Those who live through violence often suffer post-traumatic effects such as flashbacks where horrifying images of past events are constantly replayed in their mind, says Chan. These can affect the child's ability to concentrate and sleep, and their emotional state and development.

In Sichuan, she and her team met a lot of children who were scared to take afternoon naps because they were snoozing when the earthquake struck.

To discourage potentially self-destructive behaviour among the young earthquake survivors, Chan and other volunteers organised workshops for teachers and students, organising recreational activities and mobilising them to take on productive tasks, such as assisting the elderly and helping to rebuild their homes.

Adolescents are even more vulnerable. They are already dealing with a range of changes in their lives and issues of identity, says Lau. 'To help them through trauma and grief issues, you have to be sensitive to all these other needs.'