Human rights officials in Guatemala said Thursday that the victims in the major shelter fire may have been locked inside during the blaze.

The New York Times reported that one human rights official said the girls were confined to a small room after trying to escape the residence. The report said the locked door theory was a “presumption,” but there was a call to investigate who 3 died in the fire.

Nineteen victims were found dead at the scene, and 16 more succumbed one by one to their grisly injuries at hospitals in Guatemala City. Several more girls were fighting for their lives, some with severe burns over more than half their bodies. The National Institute of Forensic Science said that 17 of the bodies have been identified.

The 35th death was announced by the General Hospital late Thursday while President Jimmy Morales called for a restructuring of the country's youth shelter system, which houses some 1,500 children around the country, during a news conference. Outside the presidential palace, dozens of protesters gathered to demand answers.

The fire started when someone ignited mattresses in a dormitory.

On Thursday, distraught parents haunted hospitals and the morgue, passing scraps of paper scrawled with the names of loved ones they hoped to find.

Geovany Castillo said his 15-year-old daughter Kimberly suffered burns on her face, arms and hands but survived. She was in a locked area where girls who took part in the escape attempt had been placed, he said.

"My daughter said the area was locked and that several girls broke down a door, and she survived because she put a wet sheet over herself," Castillo said.

"She said the girls themselves set the fire," he said, adding: "She said the girls told her that they had been raped and in protest they escaped, and that later, to protest, to get attention, they set fire to the mattresses."

The Associated Press contributed to this report