Rather than running for safety, he went to the aid of victims, comforting a girl who had lost her legs, wrapping her in a T-shirt, and cradling a dying woman in his arms.

Mr. Jones, 35, says he pulled nails out of children’s arms and faces.

“Just because I am homeless doesn’t mean I haven’t got a heart, or I’m not human still,” he told ITV News. “I’d like to think someone would come and help me if I needed the help,” he said, adding that he had been overcome by an “instinct” to pitch in.

“It was children,” he continued. “It was a lot of children with blood all over them and crying and screaming.”

Mr. Parker told the news agency Press Association that amid the smoke and the shrieks after the explosion, he saw a little girl. “I wrapped her in one of the merchandise T-shirts, and I said, ‘Where is your mum and daddy?’ She said, ‘My dad is at work, my mum is up there,’” he was quoted as saying.