The two-year-old boy who was seriously hurt in a collision that claimed the lives of another two people has been discharged from hospital.

The boy was being walked by two people - believed to be the boy’s grandparents - on Coleman Rd in Wantirna South at about 12.20pm on Thursday when they were struck by an out-of-control Toyota Yaris.

The 91-year-old driver is believed to have lost control of her vehicle, striking the trio before ploughing through a fence and hitting a park bench.

The two adults are reportedly the grandparents of the two-year-old boy, as per The Herald Sun.

The 59-year-old woman died at the scene.

The 60-year-old man - understood to be the woman’s partner - was rushed to hospital with life-threatening injuries, but died on Saturday night.

The two-year-old was rushed to the Royal Children’s Hospital in a serious but stable condition.

A hospital spokesman confirmed on Monday that the child had been discharged from hospital.

Tracey Jean, one of the neighbours who was first on the scene and shielded the child after the crash, told reporters she had been in contact with the child’s parents and confirmed he was coming home and appears healthy.

“I’ll get to hold him again this afternoon,” she said per The Daily Mail.

“I’ve got a photo of him and he looks great. He really is OK.”

Ms Jean said the child’s mother rushed to the hospital to be by her father’s side before he died.

“The (boy’s) mum was texting me while she was in the hospital saying goodbye to her dad,” Ms Jean said.

“She told me that her dad is now with her mum.”

Witness Heather Webber told reporters last week she “ran straight out” of the house after haring a “funny, weird sound”.

Outside, she discovered the 60-year-old man lying on the footpath.

“There he was, the poor chap, lying on his back,” she said, adding she was “first one to see the … gentleman on the path”.

She recalled the young boy “clinging” to Ms Jean, who picked him up while Ms Webber’s husband called paramedics.

Ms Webber told reporters she was “very disturbed” by the crash and was unable to sleep on Thursday night.

The 91-year-old driver remains in hospital with minor injuries.

Victoria Police Superintendent Justin Goldsmith said last week the elderly driver was “terribly shaken” by the incident, and taken to hospital for minor injuries.

Superintendent Goldsmith said the incident was “not believed to be intentional”.

Police told NewsWire on Monday the investigation remains ongoing and they are yet to interview the elderly driver, who remains in hospital.

It is unclear if the she will be charged.