Eleven people were crushed to death as the roof of a middle school gym collapsed in northern China.

Video filmed in the city of Qiqihar in Heilongjiang Province on July 23 shows firefighters searching and rescuing at No. 34 Middle School.

According to local authorities, there were 19 people in the gym at the time of the collapse and four escaped on their own.

A preliminary investigation found that construction workers illegally placed perlite on the roof of the gymnasium during the construction of a teaching building adjacent to the gymnasium. Under the influence of rainfall, the perlite soaked up water and gained weight, resulting in the roof collapse.

An in-depth investigation is ongoing. Those in charge of the construction company have been taken into police custody.

The video was provided by local media with permission.

7月23日下午4时许，黑龙江省齐齐哈尔市龙沙区第34中学一个体育馆楼顶发生坍塌，有人员被困。
7月24日上午10时，齐齐哈尔市第三十四中学校体育馆楼顶坍塌事故救援指挥部介绍，最后一名被困学生已搜救到，已无生命体征。此次事故共造成11人死亡，事故调查工作正在全面推进中。