The 73-year-old woman had accidentally run over her husband in the driveway of their home in the Melbourne suburb of Clayton South, Australia.

Residents of a quiet suburban street rushed outside on Tuesday afternoon to find their elderly neighbour cradling her husband and crying, "I killed you my darling, my sweetheart".

The 73-year-old woman had accidentally run over her husband in the driveway of their home in the Melbourne suburb of Clayton South, Australia.

Grief-stricken neighbours say the woman was holding her fatally-injured husband and pleading with him not to die.

The terrible chain of events unfolded in front of horrified neighbours about 1pm.

The 75-year-old man was initially at the wheel of his Nissan X-Trail when he heard it making an unusual noise, Channel Ten reported.

He reportedly stepped out of the car to investigate the noise and told his 73-year-old wife to rev the engine.

But the car was still in gear and suddenly jumped forward, killing the man.

It then careered into a neighbour's house, causing minor damage.

Neighbour Andrew Boyadjian heard the woman's screams and rushed outside to find her cradling her unconscious husband.

"I looked at the poor man, he was on the ground and she was kneeling [next to] him and saying very sad things, 'I killed you my darling, my sweetheart'," Boyadjian told Channel Nine.

"She thought she was in neutral and she was in drive.

"She come out screaming. She went down on her knees, blaming herself ... saying 'don't die, don't die'."

Emergency services rushed to Ash Court in Clayton South, but the man was unable to be revived and died at the scene.

The couple had reportedly lived in the street for more than 40 years.

Their shocked neighbours were in tears on Tuesday afternoon as they spoke of a kind and generous man who they would often see walking his dog.

"He was like a father to me," one neighbour said.

Evingelos Gounrs, the man whose house was damaged by the runaway Nissan, said the couple had made him feel part of the community when he moved into the street 16 years ago.

"They were good neighbours," he said.

"Every day, every afternoon, he had the dog out walking."

Marie Milani told Channel Seven: "He just cut the grass three weeks ago in my lawn. I'm very, very sorry for them."

Acting Senior Sergeant Janine Saunders said the incident appeared to be a "tragic accident".

"Under these circumstances - these trying circumstances - police are doing the best they can, and the family are looking after each other at this stage," she said.