Local authorities apologized on Monday evening to the families of the victims, the injured and their relatives after the ceiling of a gymnasium collapsed on Sunday afternoon at a school in Qiqihar, Heilongjiang province.
"Eleven people were confirmed dead after the accident and it was the most serious security incident in Qiqihar in recent years," Shen Hongyu, the city's Party secretary, said at a news conference on Monday evening. "The provincial government has set up a joint investigation team to conduct a comprehensive and in-depth investigation into the accident."
"We will also actively do a good job of dealing with the aftermath of the victims," he said.
When the accident occurred at the gymnasium of No 34 Middle School in the city's Longsha district, 17 members of the school volleyball team and two coaches were training.
Among them, 15 were trapped and four others had managed to escape following the collapse.
"After receiving the emergency call at 2:56 pm on Sunday, a total of 700 rescue workers were put into the work," said Shen. "As of 10 am on Monday, all 15 trapped people had been located, among whom five had no vital signs when found."
The other four had suffered non-life-threatening injuries.
"We designated three first-class hospitals in the city and mobilized more than 600 medical workers to provide medical treatment," he said. "Remote consultation was carried out with Peking Union Medical College Hospital and Huashan Hospital affiliated to Fudan University in Shanghai, and the provincial Health Commission organized a group of experts from Harbin Medical University to participate in the work."
The gymnasium building is around 1,200 square meters with a steel frame; the roof was composed of a concrete slab.
A preliminary investigation found that construction workers had illegally stacked perlite, an insulation material, on the roof of the gymnasium during construction of a teaching building next to the gym. Due to recent rainfall, the perlite had soaked up water, which increased its weight and resulted in the roof's collapse.
"The public security departments have registered and investigated those responsible for the construction of the teaching building and taken criminal compulsory measures according to law," he said. "The accident exposed serious problems and we will carry out a comprehensive and in-depth special action to rectify major safety risks, especially thorough inspections of campuses, stadiums, and construction sites, resolutely eliminate safety risks, and earnestly safeguard the safety of residents' lives and property."