Parents lose their two sons, aged 2 and 6, in separate tragedies just six weeks apart.

Parents Julia and Peter Roberts have spoken of their devastation at losing their two young sons in separate accidents just weeks apart.

Their two-year-old son William Gage Roberts wandered off six weeks ago when the family were working in their yard.

Julia went looking for her young son, but started to panic when she couldn’t find him.

"That's when I called the police," she told Inside Edition.

Police searched the property for the next 12 hours, before they discovered William had drowned. His body was found face down in a creek behind the family's home.

Then, last week, the couple's six-year-old son, William's older brother, was killed in a car accident.

Peter was driving his son to school when he veered into a ditch, overcompensated and swerved into oncoming traffic on a two-lane highway.

The car they were travelling in was sliced in half, and Ayden was pronounced dead at a nearby hospital.

"I don’t know what to do from here," the boys' mother told Inside Edition.

She said her husband Peter is "not handling any of it at all."

"He's having a real hard time," she said, adding that he blames himself for their eldest son's death.

LISTEN: The Well discusses the six stages of grief.

Julia said her two boys were "best friends".

"They loved each other so much. They loved playing together. They loved sports," she said.

She said Ayden had comforted her in the weeks after her youngest son drowned.

"He tried to cheer me up most of the time. He was such a sweet boy. Last week, I was crying and he said, 'Mummy, don't cry'."

A GoFundMe crowdfunding page has been set up to help parents Julia and Peter at this difficult time. To donate, click here.