The teenage girl cowered alone at home, trapped behind bars as rampaging troops torched the buildings around her, turning them into ash.
Suddenly, one of the soldiers attacking the village in central Myanmar spotted her.
"I told you to kill everyone we see," the unit's captain told him, according to the BBC.
So the soldier shot a flare into the room and stood back as the building began to burn, listening to her screams for 15 minutes as she burned to death.
Her story is among the horrific details to emerge from the first ever series of detailed confessions to the BBC by Myanmar troops, who claim they were ordered to rape, torture and kill civilians in the aftermath of last February's brutal coup by the military.
The six soldiers, who have recently defected and are under the protection of a militia group fighting to restore democracy, spoke on condition of anonymity, providing rare insights about mass atrocities committed at the behest of the ruling junta.
The teenager was reportedly killed in the village of Yae Myet, central Myanmar, last December after helicopters dropped soldiers into the area with orders to "shoot anything you see".
The story was recounted by a man identified as "Corporal Aung" and his colleague Thiha, and corroborated by at least five witnesses who said the army entered the village in three separate groups, shooting indiscriminately at men, women and children.
"We also had an order to set fire to every large and decent house in the village," said Cpl Aung.
The soldiers paraded around the village shouting "Burn! Burn!" as they torched about 60 buildings into ashes, he said.
The corporal heard the teenager’s chilling cries as she died.
"It was heartbreaking to hear. We heard her voice repeatedly for about 15 minutes while the house was on fire," he said.
"I can't forget her shouting, I can still hear it in my ears and remember it in my heart," added soldier Thiha.
The BBC found her family, who said she had a mental health condition and had been left in her home while her parents went to work.
"She tried to escape but they stopped her and let her burn," said a relative.
The soldiers’ accounts back up multiple reports from the junta’s victims about the brutal crackdown on opposition to the military regime.
More than 2,500 civilians have been killed, over one million internally displaced, and some 11,000 have been arbitrarily detained by the military, according to Tom Andrews, the UN envoy on human rights in Myanmar.
Thiha described how young women were detained by soldiers on their way to the tailor’s, falsely accused of being militia members, and then gang-raped for days.
Maung Oo, another defecting soldier, told of a mass killing in Ohake Pho village, in Sagaing region, by the Light Infantry Division 33, which rounded people up in a monastery before shooting them from behind at close range. He said he regretted his actions.
A woman called Hla Hla, who witnessed the cold-blooded execution, said the victims included a mother who had been carrying a young child.
Hla Hla said the soldiers later boasted on the phone that it had been "delicious" to kill people and "their most successful day yet". They left the village chanting "Victory! Victory!", she said.
General Zaw Min Tun, the spokesperson for Myanmar's military, denied the BBC investigation and that the army has been targeting civilians.