Dayton, Perth: 'Scream of agony' heard before grandmother's frantic triple-0 call that three-year-old toddler had been run over

Locals have described the horrific moment when they heard a woman scream in agony after a toddler was killed when he fell out of a car and was run over.

The three-year-old boy died after he fell out of the station wagon as it headed north on Arthur Street at Dayton, in Perth's north-east, around 3.50pm on Wednesday.

The boy, who it's believed was sitting in the back of the car, suffered critical injuries and died at the scene. 

Residents in the suburban street heard a woman scream in distress before emergency services rushed to the scene. 

A nearby resident, Sinikiwe Dumba, said she went outside after she had finished work and only realised what had happened when she saw several people gathered near a park. 

'It was only after work when I came out… I saw police cars and police people manning the roads and blocking the roads,' she told the West Australian. 

'At the corner opposite the park, there were many civilians and police there and I heard a woman scream out of agony and I knew something was wrong.'

The boy's grandmother is understood to have called tripe-0 in a state of panic after he was found unresponsive. 

Officers from Western Australia Police returned to the scene on Thursday morning. 

Police were seen door knocking homes along Arthur Street.

The person driving the Kia station wagon at the time of the incident is not yet known.  

Another resident, Camila Filardo, told the newspaper it can be difficult driving a car with children seated at the back. 

'I've got 11 grandchildren and I know what it's like. I always make sure they've got seatbelts on in the back,' Ms Filardo said. 

'Major Crash investigators are conducting an examination of the scene,' WA police said on Wednesday.

Anyone with CCTV and dashcam footage or information about the incident has been urged to contact Crime Stoppers on 1800 333 000.