On a hot July day in 2007, taxi driver Salah Mutasher Toman swept his two young children into the passenger seat of his white minivan. He bade his brother, Sabah Toman, farewell and started making his way home, a short drive across the neighbourhood, through militia-held territory.

The area had echoed with explosions that morning. A fight had been brewing. But that was nothing new in Baghdad during that particular bloody summer. Salah planned on bunkering down with his family for the day to ride out the routine of heat and violence. He didn't get further than 400 metres before his van was blown apart by a hovering American helicopter. Salah died, along with six other people in his van. His son Sajad and daughter Duah were gravely wounded.

The events were all filmed by the helicopter that shot at them. The footage was among the first significant leaks from classified military materials in nearly eight years of war in Iraq. It was seen as lifting the lid on an iron-clad secrecy surrounding the US military campaign that had pitched the fighting as a black and white clash between liberators and insurgents. The civilian toll had been difficult to document and until then, impossible to film, let alone broadcast.

As the attack helicopter circled, with its cameras rolling, Salah's van entered the aftermath of an attack launched minutes earlier by the same hovering pilots. They asked for and received permission to fire, then the helicopter's guns pulverised Salah's van. Minutes later, an American patrol arrived on the scene. They approached the wrecked van and found the two children alive. They carried them straight to medics, who drove them to a nearby hospital.

"I remember them carrying me," said Duah, who was aged 4 that day and is now 7. "I was very scared and my stomach hurt a lot."

Her brother Sajad, 12, lifted up his shirt to reveal his scars. "They carried me away as well. I was terrified to be in the arms of an American soldier. But I didn't know what had just happened. And I didn't know where my sister was."

A total of 19 people, their father among them, had just been killed by the helicopter's heavy gun. Eleven had been loitering on a corner, including a Reuters cameraman. The helicopter had been circling in support of a US military operation taking place below. US troops were about to confront a militia they believed was active in the area. The helicopter pilots believed they saw some of the men armed with Kalashnikovs and another with a rocket-propelled grenades.

As rounds from the heavy guns thundered into the bitumen, the unsuspecting men standing below seemed to disintegrate. One survived and attempted to crawl until he was finished off with a second burst. Salah's minivan was on the scene around two minutes later.

His brother, Sabah Saleh Toman, had heard the first series of explosions just as has brother had pulled away from his house. "Then I heard the second [explosions]," he said. "I knew it involved him.

"My brother was only trying to help and they shot at him. They killed him. His children are almost orphans to this day, because their mother is still too [traumatised] to care for them. All day she is either in her room, or in the hospital."

Audio from the helicopter suggests the pilots had mistaken Salah's minivan for reinforcements rushing to the battle. After their initial attack on the van, a mortally wounded man was seen crawling away.

"Come on buddy, all you gotta do is reach for a weapon," one of the pilots said. Sabah and his brother's two children, whom he now cares for, have seen the footage of the attack. Parts of the footage received saturation coverage on Iraqi television channels in June.

"It was shocking to see," says Sabah. "Shocking to see how violent they were and the lack of understanding they showed. My brother arrived to help them. Anyone in this culture would have done the same."

Asked whether there were militias operating in the area that day, Sabah said simply: "Yes." He would not elaborate, but replied with another "yes" when asked whether the militia was the Mehdi Army, a key Shia lslamic player in the sectarian war that was ravaging Baghdad at the time.

In the days following the attack, Sabah looked through all hospitals in east Baghdad for his brother, niece and nephew. He quickly found his brother at the morgue, but could not locate the children. They were in a hospital in the fortified Green Zone. Duah had at least 12 bullet or shrapnel wounds al over her body. She faces more surgery and still complains of stomach pain. Sajad was just as badly wounded. When Sabah had picked up the ruins of his family, he approached the nearby US base. A colonel agreed to see him. "He took me inside and apologised," he said. "They gave me $5,000 and said that is all they could do."