OF ALL the taboos in modern China, the violent quelling of the Tiananmen Square democracy protests on June 4, 1989, remains the most sensitive.
Nineteen years later, China is now the world's fourth-largest economy, and proud host of this year's Olympic Games. But unlike other touchy subjects - Tibet, Taiwan and the Falun Gong group banned as a cult - there is no public discourse on the Tiananmen Square "incident". The real death toll is a state secret; more than a dozen protesters from that time, plus hundreds more dissidents, are in jail.
Is it fair to raise Tiananmen Square during the Olympic golden year? When the nation is mourning the almost 70,000 dead in the Sichuan earthquake, and Chinese people around the world remain sensitive about perceived anti-China bias after violent protests in London and Paris against the torch relay?
Ding Zilin, whose teenage son was one of the students killed 19 years ago in and around the square, says the Government is hoping that time and material prosperity will make people forget; that the members of a group known as the Tiananmen Mothers will die of old age and their cause with them.
Mrs Ding's long fight for justice might be a sobering thought for grieving parents now demanding political accountability for why so many schools were built so poorly that they collapsed instantly during the Sichuan earthquake, killing and injuring thousands of children.
Mrs Ding's son, Jielian, was hiding behind a floral democracy market at a road bridge leading to Tiananmen Square when he was shot in the chest. Earlier, he and classmates had appealed to the soldiers, telling them there was no violent riot needing to be quelled, but a patriotic surge against corruption and unfairness by ordinary people who believed in a better China.
When supporters mistook him for a protester and gave him food, Jielian passed it on to the soldiers.
His mother wonders sometimes if the bullet that tore through his heart later that evening on June 3 or early in the morning on June 4, was fired by a soldier who had accepted her son's food.
Mrs Ding says that if the Government has become more open after the earthquake, this has been forced by the public. But the national mourning is a watershed, she says.
"It's the first time the national flag has been flown at half-mast for ordinary people in China. In the past this was only done for leaders like Mao Zedong.
"Nineteen or 20 years cannot alleviate any of my pain," she says. "I keep asking myself if I am doing the right thing, according to what he would have wanted. If so, I will do so no matter how high the price. My son was peaceful and rational even though he was only 17 years old and politically naive."
"I feel so tired … I know that the Government is trying to postpone, postpone, postpone until people forget and the families all die. So I don't expect justice in my lifetime. The only thing I can do is to leave more and more truth for the people."
The Tiananmen Mothers group has just set up a bilingual website and published two maps, showing where the 188 known victims died and the hospitals to which their bodies were taken.
Repression is lifting - slowly, Mrs Ding concedes. Last year she was allowed for the first time to visit the site where her son died to mark the 18th anniversary. The 24-hour security guards shadowing her movements also melted away last year, although her phone is still tapped.
Last week, as the anniversary loomed, the local police rang to politely ask if Mrs Ding had her annual open letter to the authorities ready. She told him they had presented letters during the annual National People's Congress in March but there was one message he could pass up to his seniors and the central government: "When will the national flag be lowered for our children?"