Three students at a Johannesburg school were killed on Friday morning after a footbridge connecting the main school administration to various class rooms collapsed, an official confirmed.

“We received a phone call this morning from the school at about 8.10 a.m. (0610 GMT) telling us that a walkway (footbridge) had collapsed on pupils immediately after the school assembly,” Panyaza Lesufi, provincial education minister, told reporters at the Hoerskool Driehoek School.

Lesufi said 21 students had been injured and transported to various hospitals. Three of them, who got critical injuries, were airlifted, he added.

Visibly shocked and traumatized parents could be seen gathering at the Hoerskool Driehoek School to find out if their children were among those affected.

“What has happened here is very sad. When you send your child to school you don’t expect them to die or get injured,” one angry parent, who did not give her name, told Anadolu Agency.

Lesufi said the school, which has over 1,000 students, has been closed until further notice.

“For safety reasons we have taken a decision to close the school immediately,” he said. (Anadolu)