His car, a Subaru Forester accelerated backwards, pinned Mr Wiatrowski’s partner Bridget Costello, 50, and their teenage son, Xavier, to the driveway underneath it.
The 14-year-old sustained horrific injuries while Mrs Costello suffered a head injury.
The Courier Mail reports that two off-duty paramedics were the first on the scene and treated the pair while firefighters worked to cut the mother and son free.
The Queensland Ambulance Service said the woman was trapped under the vehicle for some time and had to be revived at the scene.
Tragically, Nine News reports that upon arrival at the hospital it was determined that his injuries were too severe and he had to have his leg amputated and may also lose his arm.
Ms Costello is critical condition and is understood to be clinging to life at the Princess Alexandra Hospital.
Mr Wiatrowski, an Associate Lecturer at Griffith University’s School of Human Services and Social Work, is said to be devastated and is by his wife’s side in the hospital.
Police say the terrible crash is being treated as an accident.
Our thoughts are with the family.