Father arrested after two children die inside hot car while he slept inside house

Dustin Lee Dennis had recently taken to Facebook to share his love for his children. Photo / Facebook

A US father is facing murder charges after his two young children died inside his car as temperatures hit 32C.

31-year-old Dustin Lee Dennis from Tulsa, Oklahoma, slept inside the house for five hours as 4-year-old Teagan and 3-year-old Ryan died inside his locked car.

"I can't imagine what it was like in that vehicle," said the children's aunt Chantiel Keys.

"It would have been like being in an oven."

Dennis has been charged with two counts of second-degree murder after the children's deaths, which came after a trip to a local convenience store.

Dennis returned home and went inside, falling asleep for between four and five hours.

Teagan and Ryan died while their father slept inside. Photo / Facebook

He told police he couldn't find his children when he woke and then discovered them on the floor of the car.

Police say they have received video from a neighbour which shows Dennis going into house without the children.

"'The children had not been checked on for nearly five hours during the time they were locked inside vehicle," the arrest reports states.

Dustin Lee Dennis was arrested on two counts of second-degree murder. Photo / Supplied

Keys told NBC: "All I wish is my sister had been able to save them just one more time before it had happened."

In a GiveALittle appeal, Keys revealed that the children were on visitation weekend with their father when the tragedy occurred.

"There is no way to express our grief or what my sister is going through," she wrote.

"'Hopefully they were asleep and went peacefully," an emotional Keys told reporters.

"It is a 100 per cent preventable thing that doesn't ever have to happen," she added.

"Always check your back seats."

Dustin Lee Dennis had recently taken to Facebook to share his love for his children. Photo / Facebook

The children's deaths came just days after Dennis had posted an emotional tribute to his children, who did not live with him.

Writing on Facebook, Dennis spoke of his hope for their future and said he could not "imagine this world without them".

"2 in the morning up watching my kids sleep, I can't believe they're mine, I love them so much and nobody in this world could ever make me feel as loved as they do. The other day I was so depressed because I just missed them, and I got to thinking of when they get older and become adults," he wrote.

"If you don't have kids you may not understand this but that is the scariest but most amazing thing to think of, watching them become their own person and seeing what they will experience and achieve.

"I hope our bond only grows stronger, I hope they always want to call me or see me just to talk or ask for advice. I can't imagine this world without them."

Dennis is currently being held in the Tulsa County jail on a US$750,000 ($1.15m) bond.