• Pedestrian fatally struck by truck in central Auckland named
• Pedestrians killed in two separate accidents
Mr Su died in hospital.
"He made a completely avoidable mistake and changed a life by simply being careless," Ms To said.
She said it was particularly galling that the man who had killed the love of her life was a professional driver.
Duffy had been driving heavy vehicles for a couple of years when the incident happened.
He had just got off the motorway, and before turning right, checked his mirrors to see if he could change lanes.
While doing so, he missed the lights turning red and when he realised, it was too late.
"This was a momentary lapse rather than an incident that took place for some time," Judge Christopher Field said at Auckland District Court yesterday.
Duffy earlier pleaded guilty to a charge of careless driving causing death.
His lawyer, Shafraz Khan, said the father of one was "very, very remorseful" for what happened on that stormy evening.
"This is a tragic accident and there's nothing that he can say or do that can change the circumstances," Mr Khan said. "He has to live with this for the rest of his life."
He told the court Auckland Transport had changed the configuration of the Fanshawe St traffic lights as a result of the incident, but that did not mean his client was trying to blame anyone else.
Judge Field sentenced him to 200 hours community work and banned him from driving for six months.
But it provided no solace for Ms To.
She described how Mr Su was the first person to ever recognise her potential and inspire her.
The pair were inseparable and worked hard to design and build a house where they could retire.
"Our home has now become meaningless," she said.
"I lie in bed looking at the ceiling, feeling hollow ... the dawning of a new year will never hold the same promise for me."
Judge Field ordered Duffy to pay the family of the victim $15,000 but recognised "no sum could adequately compensate the loss of a loved one".
