The power of the explosion threw the 23-year-old to the ground.
Abd Alkader Habak told NBC News he was taking pictures of Syrians being evacuated aboard buses on the outskirts of the city of Aleppo Saturday when the huge bomb hit.
Habak, a photographer and anti-government activist, said he came across children lying on the ground after he picked himself up. When Habak saw that one child was dead and another child was clinging to life, he said he stopped taking pictures.
"I couldn't believe he was alive," Habak said on the phone.
What happened next was captured by a fellow photographer and shared widely online, with the harrowing images becoming yet another window into Syria's brutal six-year civil war.
Habak said he picked up the child who appeared to still be breathing and ran to seek shelter.
"I put my camera down to help him," he said. "He was firmly grasping my hand."
It is very difficult for independent journalists to operate in much of Syria and NBC News was not able to verify Habak's account. But it was echoed by Muhammad Alrageb, the other photographer and activist nearby who captured the scene from around 250 feet away.
At least 68 children under 18 years old and 13 women were among the dead on Saturday, according to the U.K.-based monitoring group, the Syrian Observatory for Human Rights. More than 100 died in total.
Upon Habak's return to the area, he found another child who was unresponsive. He then collapsed to the ground where he is seen crying and in despair.
"It wasn't just Abd Alkader crying, other journalists did too. I turned my face away and started crying too," Alrageb, 21, told NBC News.