When Pete came home on a Sunday, he found his wife and their dogs dead.

On November 11, 2004, Pete Koutrakos sobbed in front of millions of people.

He believed he’d killed his wife in a freak accident, and was struggling to forgive himself. He appeared on The Oprah Winfrey Show to warn other people that they could make the same mistake he did.

Four months earlier, Pete and his wife Jennifer were living in South Carolina. They had been married for a year and 10 months, and together for nine-and-a-half years. The young couple also shared their home with their beloved dogs, Zena and Champ.

On a normal morning in July, Pete got up to go to work, leaving a still sleeping Jennifer in bed. Annoyingly, his car wouldn’t start. So, in a distracted rush, Pete used jumper cables and Jennifer’s car to spark his engine. He then closed the garage door on his way out, and went to work.

What he didn’t do was turn off Jennifer’s car.

Later that afternoon, Pete became concerned when he hadn’t heard from his wife as expected. Eventually, 12 hours after he had left home, he decided to go home to check if everything was okay. He had a feeling something wasn't right.

Pete's intuition was right. When he arrived home, he found the lifeless bodies of not only his wife, but also of Zena and Champ.

At first, he didn’t realise what had happened, but then he remembered Jennifer’s running car. The family had died of carbon monoxide poisoning from the fumes of the car, which had filled the house through the door connected to the garage.

Carbon monoxide is a colourless, odourless, tasteless and highly poisonous gas that is emitted when natural gas or LPG burns – such as when gas heaters are operated. It’s also produced by car engines when they are running. It’s often called 'the silent killer' because victims are often unaware they are being poisoned.

Jennifer and the dogs’ deaths were ruled a tragic accident, but Pete would always blame himself. Jennifer, a restaurant manager and devout member of the Greek Orthodox Church, was just 33.

Stricken with grief and consumed with guilt, Pete told Winfrey that while he recognises on a rational level that he didn’t intentionally kill his wife, he struggles to forgive himself for his actions that day.

“I know it was a mistake, and mistakes happen every day. It was a split second of forgetting,” he said, as Winfrey consoled him.

“Initially, you blame yourself. It’s like, ‘Why didn’t I shut the car off? Why didn’t I shut the car off?’

“You go, ‘Why?’ and you can’t do that. You can’t ‘Why? Why?’ all the time. You’ll go nuts.”

Sobbing, with red eyes and a scrunched tissue in one hand, it was clear that Pete was still consumed with thoughts of what he could and should have done differently.

Confined space fatality expert Dr Ciaran MacCarron told the ABC: "Between four to six minutes turns a rescue into a recovery” – meaning that carbon monoxide poisoning can become fatal very quickly.

Pete admitted to Winfrey that he wished he had acted sooner on his instincts to check on his wife, and it was something he still grappled with.

Looking back at the interview seven years later, Winfrey suggested there was a lesson in the tragedy for all of us.

“I remember Pete’s grief was so raw, it was palpable to everyone in the studio that day,” she said.

“On the surface, it looks like, ‘Oh, a lesson about carbon monoxide poisoning’.

“And it looks like a lesson about leaving the car on in the garage. But it really is about present moment. This present moment, and staying in the consciousness of this present moment.”

Fifteen years since the tragedy, a glance at Pete’s public Facebook profile seems to reveal that he’s worked hard to rebuild his life and move forward. Now working in the live music industry, he also appears to have found love again in 2015, with a woman named Amy Dalton.

Carbon monoxide poisoning in 2019.

It’s important to note that last year, The New York Times reported that keyless entry cars were responsible for fatalities because motorists think an engine has been turned off simply by their clicker being removed from the vehicle.

For further information on carbon monoxide poisoning in general, see The Chase and Tyler Foundation.