A primary school student has died in a stampede in which 20 more were injured, Party-affiliated news website k618.cn reported Wednesday.

Initial reports said that the incident happened while a group of students were going to the bathroom and may have been caused by a wall collapsing. However, state broadcaster CCTV later refuted this information, saying instead that the stampede began when students fell while descending a staircase.

A local publicity official also denied social media reports that the cause of the stampede was the collapse of a bathroom wall. Earlier reports erroneously said that two pupils had died.

The stampede happened around 8:30 a.m. on Wednesday at the Number 3 Experimental Primary School in Puyang County, in central China’s Henan province.

The school’s headmaster has been fired, k618.cn said.

A photo circulating online shows adults tending to a child who is lying on the pavement. A small crowd had gathered at the school gate, according to video footage, which also included chaotic scenes at a hospital.

(Header image: Parents crowd outside the gate of the No. 3 Experimental Primary School in Puyang County, Henan province, March 22, 2017. From Weibo user @Lyyizhihenanjing52521)