Every once in a while, Mr Wong would see a blue police tent in his grey Kallang neighbourhood.
Once, the body inside the tent was that of someone he knew, an elderly neighbour, said the 60-year-old, who wanted to be known only by his surname.
"He went up to the highest floor, took off his slippers, and jumped down," said Mr Wong, who discovered the details from other neighbours. At least two elderly people commit suicide every year in his area, added Mr Wong, a retired businessman who used to sell bottled water in Indonesia.
His neighbourhood, which lies across the river behind the Immigration and Checkpoints Authority building, has an estimated 3,000 seniors living in one- or two-room rental flats, often alone.
"A lot of these people have nothing to look forward to," said Mr Wong, a single who has been living alone in a rental flat for nearly 15 years. He spends his time reading newspapers or taking walks around the neighbourhood.
SAMARITANS OF SINGAPORE (SOS): 1800- 221-4444 (24-hour)
SINGAPORE ASSOCIATION FOR MENTAL HEALTH: 1800-283-7019
INSTITUTE OF MENTAL HEALTH MOBILE CRISIS SERVICE: 6389-2222 (24-hour)
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SENIORS HELPLINE: 1800-555-5555
Family members and friends can help to identify an elderly person at risk of suicide. Here are some warning signs to look out for:
• Expressions such as "Life is too painful for me"
• Words about bidding farewell, such as "Take care when I'm gone"
• Behaviour that suggests preparation for suicide, such as tidying up one's affairs and giving away treasured items
• Dramatic changes in mood
• Intense feelings of hopelessness or helplessness
• Feeling psychologically and emotionally trapped - like there is no way out
• Withdrawing from family, friends or society
•Source: Samaritans of Singapore
Last Thursday, The Straits Times reported that more people aged 60 and above are taking their own lives. Last year, 126 people from this age group killed themselves, up from 79 in 2000.
While the suicide rate among seniors has stayed relatively stable over the past five years - the proportion of elderly suicides has risen in tandem with the proportion of elderly people - there is concern that the absolute numbers could rise further as Singapore's population ages.
There are now around 460,000 Singapore residents aged 65 and older. This figure is expected to double to more than 900,000 in 15 years.
Ms Chan Wai Ping, a counsellor at Tsao Foundation's Hua Mei Centre for Successful Ageing, said: "Some of the elderly folk who have lost their loved ones or friends of many decades feel generally less needed and useful, and they find their new stage of life meaningless.
"When they are not connected with others, they may also have less opportunity to be exposed to more life-affirming perspectives."
In many cases, loneliness, illness or financial woes play a role in driving seniors to take their own lives.
A study of more than 2,500 elderly Singaporeans released on Friday found that those who lived alone were 1.7 times more likely to die prematurely - although not necessarily by suicide - compared with those living with others.
Men who lived alone were nearly three times more likely to die prematurely than their counterparts who lived with others.
The study also found that elderly people who lived alone were about twice as likely to suffer from depression and loneliness.
Mr Edmund Song, executive director of RSVP Singapore, a non- profit organisation of senior volunteers, said: "Some seniors feel lonely as they may be new retirees adjusting to a new phase of life or experiencing the 'empty nest syndrome'."
Elderly people with limited eyesight and mobility issues are also more likely to feel lonely, said Associate Professor Angelique Chan of Duke-NUS Graduate Medical School. She led a study, released last year, which found that feeling lonely raised a person's risk of dying by 34 per cent over a four-year period, compared with those who were not lonely.
The feeling that one's life lacks purpose arises partly from living alone, said experts.
Mr Wong added: "Some people can be very desperate and not know who to go to for help when they run into financial problems."
Others may not want to be helped, for fear of being a burden to their loved ones, said Ms Chan.
Ms Christine Wong, executive director of suicide prevention agency Samaritans of Singapore, said: "The sense of hopelessness and despair at the height of a crisis can cause people to contemplate suicide as a means of escaping their emotional pain and from being a burden to their families."
Experts said many helping hands are required, and members of the public could be educated on identifying signs of suicide risk.
There are welfare groups that organise programmes for the elderly at senior activity centres (SACs) and send volunteers to visit them or take them to their medical appointments.
Prof Chan suggested that more resources be channelled to befriender schemes which specifically reach out to elderly people who may not go to day-care centres or SACs.
But what about those who may not even be willing to open their doors to well-meaning visitors?
Ms Tin Pei Ling, Member of Parliament for MacPherson which has a high proportion of elderly residents, said it is a "labour-intensive" effort for help groups and grassroots leaders to reach out to the elderly. "You need to spend a lot of effort to keep knocking and hopefully break the ice. There are no shortcuts, especially if there aren't family members to help," she said.
As for Mr Wong, he occasionally takes part in activities organised by the SAC located at the void deck of a block near his home, or simply drops by to read the newspapers.
But others, like 69-year-old Mr Ling Teng Hua, prefer the solitary life and do not like group activities. Mr Ling lives alone and has never been married. The retiree used to do odd jobs such as selling fruit and washing cars.
"It's in my character, I don't need to rely on anyone," he said. "By living alone, I can do whatever I like, and there are no problems or quarrels."
Retired tailor Chee Ng Mooi, 67, shares a rental flat with a friend. She is separated from her husband, and sees her three children only occasionally. But she said she is too busy to feel lonely.
She goes for dance classes and karaoke twice a week, and singing lessons once a week.
"To be honest, my children don't take much care of me. Sometimes when I call them for a meal, they don't pick up or they say they're busy," she told The Sunday Times.
"But if you take these things too much to heart, you will die. You have to try your best to find happiness where you can - who else is going to give it to you?"
•Additional reporting by Janice Tai