Roof collapse kills 11; probe underway

Those responsible have been taken into police custody.

Perlite "is often used in external wall insulation", a construction industry staff member surnamed Chen told Shanghai-based Xinmin Weekly. "It will gain more than 10 times its weight after absorbing water."

"With quite a large area, gymnasiums seldom use pillars in the middle to support the roof, so the roof's load-bearing capacity is very low," said Chen. "The roof is like a huge tent, and the stacking of building materials on it should not have been allowed."

The father of a trapped student told Beijing Daily that his 16-year-old daughter and other members of the school volleyball team had been training at the school for an upcoming competition in Hubei province. It was not immediately known if his daughter was among the survivors.

On Sunday night, the provincial government held a video conference on safety work in Heilongjiang to provide information on the roof collapse and other recent accidents.

These accidents "exposed serious problems", said Heilongjiang Vice-Governor Wang Yixin. "It is necessary to carry out special rectification of safety risks, strengthen management of any dangerous buildings" and take steps to ensure the safety, he said.