Macabre trend that began in HK in 1998

In November 1998, a middle-aged woman in Hong Kong began a deadly trend when she sealed the door and windows of her bedroom, lit a small pile of barbecue charcoal and lay down to die.

Within two months of that lonely act - vividly covered in newspapers - charcoal burning had become the city's third-most common method of suicide.

Twelve years and thousands of deaths later, it is a truly global phenomenon. It is the leading method of suicide in Taiwan, and in 2007 the lead singer of American rock band Boston killed himself at home in New Hampshire by burning charcoal.

Since that first death, the University of Hong Kong's Centre for Suicide Research and Prevention has been monitoring the trend - and early on it identified an important factor: people who commit suicide by charcoal burning are different.

'Usually, the people who commit suicide are unemployed or elderly or have mental illnesses. These are the groups traditionally at higher risk,' the centre's director, Dr Paul Yip Siu-fai, explained.

'But with charcoal burning, people are middle-aged, they are less likely to be suffering from any mental illnesses, they are employed, and they have financial problems to a greater extent than those who die from other forms of suicide. These are people who don't find the idea of jumping or hanging appealing as a method of suicide.