'I thought if such a girl can be so brave ... it gave us all courage'

As gunfire and screams echoed through an upmarket mall, families drew on inner reserves to survive

It was one of the most moving images of Kenya's Westgate Mall attack - a little girl running in terror across an empty corridor to the outstretched arm of her rescuer.

Now it is possible to tell the remarkable stories of the child and her saviour. Portia is the four-year-old daughter of American expatriates Katherine and Philip Walton, both IT workers.

The man who saved her, along with her mother and two sisters, is Abdul Haji, a Somali Muslim and the son of a former security minister in the Kenyan government.

Faced with a long afternoon trapped in the house with her five children on Saturday last week, Katherine Walton decided on a quick excursion - a trip to Nairobi's popular mall. Her two teenage boys went ahead and Walton followed soon after with her three daughters, including Portia.

Four hours later, the family lay pinned to the ground opposite the supermarket where they did their weekly shopping as gunmen hurled grenades and sprayed bullets just metres from them.

"We were just going to meet my two older boys in the supermarket when we heard an explosion," said Walton, 38, from North Carolina. She moved to Kenya with her family two years ago.

"I grabbed the girls and started running. A woman pulled us behind a promotional table opposite. I could see the bullets hitting above the shops and hear the screaming all around us."

She remembers only fragments of the hours that followed, which she spent huddled under the table - but, according to Philip Walton, 39, she saw enough of the attackers to be able to describe several of them in detail afterwards.

"She heard them talking to people, telling them to stand up, followed by gunshots," he said. "The thing that's troubling her now is she can't forget the smell of the gunpowder."

During their ordeal, the couple's three daughters, aged four, two and 13 months, were shielded and calmed by an injured Kenyan woman and two Indian women who hid with them.

"They were so still and quiet," Katherine Walton said. "My baby was screaming when there was shooting, but between that she just slept. In one lull in the fighting, my two-year-old and the baby were playing together with my phone. I couldn't understand how they could be acting like everything was fine."

Metres away from them, she saw a man with a pistol who was shooting at a heavily armed young jihadi in a bandana, who was taunting him to come closer.

That man was Abdul Haji, who had rushed to the mall after getting a text message from his brother, who was trapped inside.

"We saw a lot of dead people. Very young people, children, old ladies - you cannot imagine," Haji told the Kenyan television station NTV.

"From what they were doing, you could tell that these were not normal people. The fact that he was making a joke out of this whole thing made me much more angry and determined to engage them and to shame them."

Haji said his father taught him to use a gun to protect their cattle from bandits when he was growing up.

He used his skills to provide fire cover for Kenyan Red Cross workers and, over a period of three hours, help to evacuate some of the 1000 people who escaped the mall in the initial stages of a siege that would last three days and leave at least 72 people dead.

As he stood with a fellow rescuer crouched outside the Nakumatt supermarket, Haji said, he noticed the women hiding under the table.

"Just a few minutes ago we were exchanging fire with the terrorists, and these people were right in the middle of it, in the crossfire. We regrouped and we started to strategise on how to get them out of there," he said.

He asked the women to move towards them, but they indicated that they had children with them and could not all run together. Haji asked Walton if one of the older children could be encouraged to run towards him. Portia emerged and ran across the deserted corridor.

The moment was captured by a Reuters photographer, Goran Tomasevic, in a dramatic image that was sent around the world.

Philip Walton, who during the siege was on a business trip to the US, said he reacted in disbelief when he first saw the photograph of his daughter striking out alone across the mall. "She's not normally the kind of girl that would run to a stranger, particularly one with a gun," he said.

His wife added: "I don't know how she knew to do it, but she did. She did what she was told and she went."

Seeing the little girl running towards him gave Haji fresh impetus to continue helping people out.

"This little girl is a very brave girl," he said. "Amid all this chaos around her, she remained calm. She wasn't crying and she actually managed to run towards men who were holding guns. I was really touched by this and I thought if such a girl can be so brave ... it gave us all courage."

One by one, the Walton family emerged and ran with Haji and other rescuers until they reached police lines outside the mall.

There, Katherine Walton was reunited with her teenage boys, who had been trapped with another family in the basement of the mall but had also escaped.

Looking at the photograph now, Walton said she could see the fear etched on her daughter's face. "I was worried about family in America seeing it, because we haven't really shared the whole story with them yet," she said. "For me, I know the story behind it and that it ends well. I think I owe Mr Haji a hug or two."