Young mother Priya Muthu was supervising construction work on her north shore property on Wednesday evening when tragedy struck.

With her four year-old son Prahlad in her hands, she was pinned beneath a tipper truck that toppled over as it careered out of control and rolled backwards down a sloping, dirt driveway.

Ms Muthu, 30, died at the scene. Her son was taken to hospital with minor facial injuries.

The truck was carrying soil and rocks and was working on a subdivision on the Wahroonga land owned by Ms Muthu and her husband, Babu Manivasagam Narayanan Soundara.

Its 67-year-old driver was not in the vehicle at the time of the incident and witnesses said he appeared devastated as he spoke with police at the scene.

It’s believed Ms Muthu had attended the investment property on Spurgin Street with her son to oversee construction work on a second home to be built at the back of the property.

Tenants who lived in a small weatherboard home at the front of the property said Ms Muthu was a kind, helpful women and a good landlord.

"She's very good, she's very kind, very helpful when we needed some help," Guiseppe Gargiulli said. "She's a very good landlord."

Mr Gargiulli, who lives at the home with his wife Valeria Miassedova and daughter Anastasia, said he was cooking dinner on Wednesday when he heard "bang noises" at around 5pm.

"I heard big noises, I came outside and I heard the child say 'mum, mum'," he said.

Mrs Miassedova and her daughter ran outside to see the woman pinned beneath the truck and they called an ambulance.

Emergency services arrived to find the truck tilted on its side at the side of the house at the end of a short, steep driveway.

Mess and soil from construction work in the front yard has done little to hide the damage caused. Twisted metal poles, snapped wooden planks and tipped fences lie in a jumble along the driveway.

A real estate agent who sold the land to Ms Muthu and her husband four years ago and has remained friends with the family since said she was a ‘‘caring mother’’ who was always smiling.

‘‘She was a caring mother and she always smiled and she is such a nice person,’’ he said.

Ms Muthu had worked in IT for charity organisation Wesley Mission for the past five years.

Wesley Mission chief executive, the Reverend Dr Keith Garner, said she was warm, gracious and dedicated.

“Priya was a well-respected and loved member of our Information Services team, who, like us all, are devastated by the news of her death," he said. “Her warm and gracious manner was cherished by all her worked with her."

He said the organisation would be praying for her husband Babu and their son Prahlad.

“It is at such times that we are conscious of the fragility of life and the need of each other," he said. "Words cannot fully express how we feel.”

Police from Ku-ring Gai Local Area Command are continuing their investigations and will prepare a brief for the coroner.

with Saffron Howden