NYERI, Kenya – Thousands of mourners stood before rows of small white coffins on Thursday at a memorial service for 21 children who died in a boarding school fire in central Kenya earlier this month.

The coffins were topped with bouquets of flowers and photographs of the young boys from Hillside Endarasha Academy in Nyeri town, most between nine and 13, trapped in their dormitory.

“To come to Nyeri and see all these coffins, this is one of the greatest national tragedies that we’ve had in our country,” said Eugene Wamalwa, an opposition party leader.

Kenya has a sad history of school fires. There were more than 60 cases of arson in public secondary schools in 2018, according to most recent data in a parliamentary report.

It is not yet known what caused the fire at Hillside Endarasha Academy, but researchers say many similar fires have been set by students protesting harsh discipline and poor conditions.

In 2017, ten girls lost their lives in a high-profile fire at a school dormitory in Nairobi. A teenage student was charged with manslaughter for committing arson.

Maryanne Mwangi’s 14-year-old daughter, Virlear, was among the victims. When she heard about Endarasha, Mwangi was angry that the government’s creation of various task forces had done nothing to improve conditions in schools, she said.

“I (didn’t) want to look at social media because I’m telling myself, ‘it can’t be happening again,'” she told Reuters.

“I always prayed Bubbles will be the last child who will die of a school fire,” Mwangi said, using her daughter’s nickname.

Kenyan boarding schools often impose too many strict rules, creating discontent that lead some teenagers to commit arson so they could go home, Mwangi said.

“Our schools are a school of rules. It’s actually like a military camp,” she said.