The self-inflicted deaths of seven young people in a south Wales town within the last 12 months has led to speculation that police might be dealing with what experts term a suicide "cluster".
Dead at age 17, Timothy's mother says he too was a "cluster" victim
All the victims were young, lived in the same small area and, according to police, knew each other "as you would expect in small neighbouring communities."
Cluster suicides are rare events, but when they happen they affect not just individual families, but sometimes whole localities.
Bonnie McCelland, 58, has felt at first hand the devastating fallout of a "cluster" suicide. First her only son Timothy killed himself after suffering depression.
A single mother without the support of a partner, she then had to face the grieving parents of two of Timothy's friends, who also killed themselves shortly after his death.
"As a parent, your heart is already shattered," she said. "But then, to look into the eyes of your friends and see the pain that your child has caused, is something you carry in your heart forever."
She attempts to shed light on the reasons why a young person, with their life ahead of them, might choose to follow a friend into suicide.
"When a suicide happens it's like a book has been taken off the library shelf," she said. "They open that book, and it gives them the direction of what to do."
Ms McClelland now works to raise awareness of teenage suicides in her local town near Tampa in Florida. In the year following Timothy's death, she says there were 29 teenage suicides in her local area.
And her message to parents everywhere is: "Talk to your children about their feelings.
"If they are depressed or are thinking about self-harm or suicide - ask questions, and be honest about the answers you give."
Last week she commemorated the sixth anniversary of the death of her son "aged 17 years, six months and 11 days" .
Timothy had been suffering depression - which his mother says runs in the family - from the age of 15. He was a "very bright" child with lots of friends. But he was dyslexic, and found school frustrating.
An incident of self-harm and threats to kill himself led to him being sectioned twice under Florida's mental health laws.
"After he burned himself on the arm that first time, I asked him why he was so sad, and he said, 'Mom, I hate my life'. I asked him what's to hate - but he couldn't verbalise it," says Ms McClelland.
Eventually he was suspended by his school and from then on, says his mother, it was a "roller-coaster" of emotions until one terrible day in January 2002 she opened his bedroom door and discovered his body.
It was two weeks after a 15-year-old called Charles Bishop killed himself by flying a Cessna light aircraft into a Tampa skyscraper. Ms McClelland firmly believes that Timothy was inspired to follow suit.
If so, it made him the first copycat suicide in a rash that eventually claimed at least four young lives.
Bonnie McClelland won't go into detail about how her son killed himself. "Too many details might encourage other people," she says.
Natasha Randall, 17, was found hanged at her home in Blaengarw
But nine days after Timothy died one of his friends killed himself "using the exact same method Timothy used," she says. "That's how I knew it was a copycat too."
"What I couldn't understand is how he could have done it after he went to Timothy's service and saw how people were devastated by his death."
And five weeks after that, another teenager from the same school killed himself..
Now, after six years of grieving and trying to make sense of her son's death, Ms McClelland has thrown herself into a campaign to make parents more aware of the dangers of teenage depression.
"My advice is: ask your children those difficult questions - are you depressed? Do you want to kill yourself? And if the child says yes, then ask them how they plan to do it," she says.
"Anything that gets them thinking about the real consequences of their actions is good."
As well as devastating families, whole communities can go into shock after a cluster of suicides.
Last summer three teenagers from the same school in County Armagh, Northern Ireland, killed themselves within a month of each other.
Six months later the local vicar, the Rev Brian Harper, still won't talk about the suicides. "It's too raw," he says. "We're advised that it will take at least two years for us to get over this."
Cluster suicides are still little understood by the experts - but the first comprehensive study is now being led by American psychologist Professor Madelyn Gould of Columbia University.
She has pinpointed 53 suicide clusters around the US and is trying to find if there are common factors involved.
To qualify as a cluster for her research, there must be between three and 11 victims, aged between 13 and 20. And all must have killed themselves within 12 months of the first death.
CLUSTER SUICIDE STRATEGIES
Avoid glorifying suicides
Offer support to families and friends of victims
Identify vulnerable relatives and friends and offer counselling
Enlist the support of the media
Source: US Centre for Disease Control
So far the clusters have thrown up few things in common - apart from having a tendency to take place in smaller communities, where people are more likely to know each other.
"What we are finding is that victims of cluster suicides are usually not best friends, but they know each other, or have heard of each other," says Professor Gould.
One disturbing factor is the role of the media.
Says Professor Gould: "We are finding that the more sensational the coverage of the suicides, and the more details the media provides, then the more likely there are to be more suicides.
"If the suicide victim comes to life in the newspaper article, or the reasons for dying are presented in a compelling way, then suicide can become more attractive to a vulnerable person.
"It's like the first person who commits suicide becomes a sort of role model for those who come afterwards.
"And if you are vulnerable and depressed then the fact that someone has gone ahead and done it might be enough to tip the balance inside your mind.
"Suddenly, suicide becomes a realistic option."
Professor Gould offers the same advice as Bonnie McCelland gives to the parents of potential cluster-suicide victims.
"Address the issues honestly with your children. Talk to them."
"If you are a community, don't close down - welcome in the professionals who might help you get through this.
"And above all don't deny it is going on."