He ran to the property and was confronted by the horrific scene: the car was ablaze with flames up to 5m high and a woman in only her underwear was lying beside the vehicle. She was face down and a large amount of skin had been burned off her body.
"Her face was badly burned and the rest of her body was completely burned."
"A young girl called her name and she raised her head."
Cornes estimated the fire had been going for several minutes before he arrived and he was told the woman, whom he believed was in her 50s, had got out of the car by herself.
"Others said she was sitting inside the car and it caught on fire. They used a fire extinguisher. I saw her clothing burning. They had already taken the clothes off and put them into the gutter. There were flames half a metre high [coming from the clothing]."
Cornes said bystanders feared the car would explode and seemed unwilling to go near, but he looked carefully and was confident the petrol tank was not on fire.
When he realised the woman was alive, he thought to himself: "I can't let her die."
With two men, he went towards the burning car to move the woman away but one of the other men found the task too difficult.
The two remaining rescuers dragged her away. The woman was placed in the recovery position and towels were placed over her, which neighbours kept wet with hoses until ambulance officers arrived.
Cornes said the woman, although conscious, was unable to speak.
He said it was a mystery how the fire started.
The police said later that a person had been taken to hospital with critical injuries. They were working with Fire and Emergency to establish the cause of the fire.
An Auckland Hospital spokeswoman said the person was in a critical condition and had been transferred to the Middlemore Hospital burns unit.
To the suggestion he had acted heroically, Cornes said: "No. Everybody contributed. It was a great team effort. I'm proud of the whole neighbourhood."