The blaze that has killed at least 37 and maimed others at an overcrowded Guatemalan shelter for abused teens broke out in a tiny room they were locked in to control them after a riot at the center, authorities and witnesses said.

The inferno in the 16 square meter classroom packed with 52 teenagers left survivors of Wednesday’s blaze with such severe injuries that burn specialists were flown in from the United States and medics said they needed hundreds of blood donors.

Hospital officials on Friday said two more girls had died overnight and that more than a dozen remain hospitalized in critical condition.

The government has sacked the director of the Virgen de la Asuncion home, temporarily closed the center, declared three days of mourning and vowed to reform a childcare system that experts say is critically underfunded.

“The staff left the girls in an extremely reduced space, a four-meter by four-meter room, for 52 teenage girls,” said Claudia Lopez, Guatemala’s deputy ombudsman for human rights on Thursday. “It was a terribly thought out decision.”

Police and witnesses say the fire appeared to have been started by one of the girls, who set light to a mattress in the room, possibly as a protest after hours inside.

“If it really was the girls who started the fire - why did they have matches in their hand, why were they not searched if they were going to be locked into this tiny space?,” Lopez said.

ATTEMPTED ESCAPE

The Virgen de la Asuncion home houses youths up to 18 years old on the pine-wooded outskirts of the municipality of San Jose Pinula, some 25 kilometers (15 miles) southwest of the capital Guatemala City.

Its residents are an unusual mix of victims of violence and young offenders, with children with disabilities in another wing.

Years of problems at the home boiled over at lunchtime on Tuesday when a group of teenagers complaining about the conditions inside feigned a fight in the lunch hall as a distraction, before attacking staff and trying to escape, one eyewitness said.

After hours of rioting, police captured most of those who had fled and they were separated from the hundreds of other residents in the complex, according to an account written by the government’s human rights department and seen by Reuters.

During five hours of negotiations that evening, the leaders of the rebellion alleged abuse by the staff including rotten food and the use of bleach on their skin and pepper spray as punishment for bad behavior, according to the document.

SMOKE SEEPS OUT

At around 1 am, the 52 girls were locked into a classroom and given thin mattresses to sleep on, local police chief Wilson Maldonado told a congressional commission. Boys involved in the trouble were kept in a separate area, an employee at the home said.

At about 9 am, police stationed outside the room noticed smoke seeping out, Maldonado said. However, one witness said the fire started 30 minutes earlier and police initially ignored the cries for help, thinking the girls were protesting.

“I heard shouting and loud noises all night,” said a teenage girl who witnessed the fighting in the lunch hall and said she spent much of the Tuesday cowering under a bed in her dorm after some of her peers tried to make her join the riot.

“The fire was at about 8.30 am, the boys came running down to say that a girl had died,” she said. “The police grabbed the boys and a carer began hitting them and telling them off for having left the room they were left in.”

“TIP OF THE ICEBERG”

The Virgen de la Asuncion center has a history of abuse accusations documented by Guatemalan media. Over the last three years more than 250 of its residents have fled, newspaper reports said.

Human rights reports and interviews with people inside the center paint a complex picture. Some residents felt the center provided them shelter and education their families couldn’t, and blamed a few “rebels” for the tensions.

Speaking to Reuters on condition of anonymity, an employee who has worked there for six years attributed many of the problems to low funding, poor staffing levels and judges who sent a steady flow of youth offenders to the home, rather than to detention centers.

“We had 15-19 new arrivals a day, every carer had 34 children to look after, and we were on one day on, one day off shifts of 24 hours because there were not enough staff, “the employee said, adding she faced death threats and verbal abuse from her wards.

Guatemala has Latin America’s worst rates of child malnutrition. Street gangs like the Mara Salvatrucha prey on minors. And, the Central American nation’s public institutions are underfunded, racked by corruption and widespread overcrowding.

The situation has contributed to the exodus of at least 67,000 Guatemalan children to the United States since 2013.

“What happened in the secure home yesterday is just the tip of the iceberg of an entire system of not protecting children and teens in Guatemala,” said Enrique Maldonaldo, a specialist in child studies at the Instituto Centroamericano de Estudios Fiscales.

“Guatemala has not been capable of guaranteeing a minimum level of social protection,” he said.