The fathers visited Mr. Huang at the Tianwang Human Rights Center, an informal advocacy organization in the provincial capital of Chengdu, where he worked and lived. They told him how the four-story Dongqi Middle School had crumbled in an instant, burying their children alive.
Mr. Huang soon posted an article on his center’s Web site, 64tianwang.com, describing their demands. They wanted compensation, an investigation into the schools’ construction and for those responsible for the building’s collapse to be held accountable — if there indeed was negligence.
A week later, plainclothes officers intercepted Mr. Huang on the street outside his home and stuffed him into a car. The police have informed his wife and mother that they are holding him on suspicion of illegally possessing state secrets.
“They’ve been using this method for a long time,” said Zhang Jianping, a contributor to the Web site who has known Mr. Huang since 2005. Nobody knows the grounds for his arrest, but many people have the same idea. Mr. Zhang said, “It may be because the schools collapsed, and so many children died.”
In the days after the earthquake, the authorities allowed reporters and volunteers to travel freely in the disaster zone. Some commentators even saw the dawning of a Chinese glasnost. In an interview with National Public Radio that aired in May, Mr. Huang said he believed that the human rights situation in China had greatly improved.
“He actually thought things were heading in the right direction,” said John Kamm, who is pressing for Mr. Huang’s release and is the executive director of the Dui Hua Foundation, which has helped free prominent Chinese political prisoners. “That’s one of the tragedies of his detention.”
A volunteer at the Tianwang center, Pu Fei, 27, was detained minutes after Mr. Huang. He said that the officers who interrogated him demanded that he hand over the password needed to post information on their Web site. They also wanted to know whom Mr. Huang had met and where he had gone in the disaster zone. Mr. Pu was detained in a hotel for two weeks and then released.
Mr. Pu and other volunteers said the authorities might have singled out Mr. Huang because he disseminated information about parents whose children had died in collapsed schools — a group whose protests began to snowball into something like a movement in early June.
There is no official figure on how many children died in schools during the powerful May 12 earthquake. Seven thousand schoolrooms collapsed, according to Chinese government estimates. Thousands of students may have died, if not more, leaving behind bereft parents looking for answers.
During the brief period of openness in late May and early June, parents marched with photos of their children and gathered at the wreckage of schools to hold memorial services. They held sit-ins outside government buildings. In one town, the top Communist Party leader got down on his knees and begged parents to stop a march, but they refused.
But with the Olympic Games in Beijing approaching, the issue increasingly looked like a time bomb for the authorities, and they scurried to defuse it. The Propaganda Department banned coverage of destroyed schools in the domestic press. Paramilitary police officers blocked foreign reporters from demonstrations. Activists who tried to gather and publish information about school construction were detained.
On June 2, The Sichuan Economic Daily published an article saying that substandard construction methods contributed to the deaths of 82 students at a middle school in Yinghua Township. Afterward, an editor at the paper said, two reporters and an editor who worked on that article were fired.
Two fathers of children killed in schools said in separate interviews that officials had told them public gatherings and petitioning the government were no longer permitted. Zeng Hongling, a local crusader who wrote three articles lashing out at the government’s earthquake response, was detained on suspicion of inciting subversion, according to the Information Center for Human Rights and Democracy, a group based in Hong Kong.
Mr. Huang, who was detained on June 10, has not yet been formally charged with any crime. But if he is convicted on the murky charge of holding state secrets, it will not be his first time being jailed for a political crime.
In 1998, he and his wife, Zeng Li, founded the Tianwang Center for Missing Persons, an organization that focused on cases of human trafficking. Its name later changed to Tianwang Human Rights Center as its mission expanded.
In 1999, she and Mr. Huang helped the police rescue seven girls who had been sold into prostitution. The case gained the Tianwang center favorable attention in the state-run news media.
Mr. Huang also exposed a racket through which thousands of migrant workers sent to work on ocean-going fishing boats had been forced to pay for mandatory appendectomies at a government-run clinic. He published an article on his Web site. His wife said that Mr. Huang’s report stepped on the toes of high-ranking local officials who profited from the arrangement.
Mr. Huang continued to post articles about other taboo topics.
In March 2000, he wrote about a practitioner of the banned spiritual group Falun Gong who was beaten to death in police custody. The Chengdu police shut down his Web site days later, so Mr. Huang moved its content to a server in the United States.
Later that year, he posted an account of a 15-year-old boy who was detained in Chengdu during the 1989 pro-democracy demonstrations in Beijing. The boy later died in police custody.
The police arrested Mr. Huang shortly thereafter. He was held for an extended period without trial, and he was ultimately convicted on charges of inciting subversion and was sentenced to five years in prison. Ms. Zeng, who has lived apart from Mr. Huang since 2006, said the experience changed him.
“When he came out, you could see scars on his head,” she said. “He became irritable, and he would forget things.”
To the surprise of some friends, Mr. Huang took up where he had left off when he got out of prison. He revived his dormant Web site, found citizen journalists throughout China to contribute articles and resumed his role as an activist. “He started helping petitioners — people who had been harmed, people whose homes has been demolished, people whose rights had been abused,” Ms. Zeng said.
State security agents watched him, Ms. Zeng said, but they did not interfere with his work.
Then the earthquake hit, and foreign reporters flooded the devastated towns. Mr. Huang knew the terrain of Sichuan well and did his best to help. He accepted interviews with the foreign press. He and his volunteers rented a truck and handed out bottled water, instant noodles and crackers to refugees. In June, he helped reporters from a British television channel contact parents whose children had been killed in schools destroyed by the earthquake. And he began acting as a clearinghouse of information for reporters.
Mr. Huang kept in touch with the five fathers whose children had died at Dongqi Middle School. They joined a group of experts to investigate the wreckage for clues as to why the building crumbled. Mr. Huang posted a short article on his Web site saying that, according to the experts, the school was structurally unsafe.
It was one of his last postings before his detention. Mr. Huang’s lawyers and family said that the Chengdu police have denied their requests to meet with him on the grounds that his case involves state secrets. Officers with the Wuhou District Public Security Bureau declined to comment, saying they were not authorized to speak with the media.
A conviction for the crime of possessing state secrets can carry up to three years in prison.
It is unclear whether the pressure to arrest him came from central authorities in Beijing or from local officials, who regarded his criticism of the collapsed schools as threatening. Mr. Pu said that some of the officers who interrogated him spoke with a northern Beijing accent, which is unusual in Sichuan, an area with a strong dialect.