One man reached into the car and appeared to be punching Mr Hadfield, before leaving.
Clutching his chest, Mr Hadfield got out of his car and almost immediately collapsed. Despite efforts by residents and then police to help him, he died soon afterwards.
Mr Hadfield's extended family have been gathering this weekend to support his partner and young children, 5-year-old daughter Aaliyah and 2-year-old son Kayleb.
Yesterday his body was taken to Te Mangungu Marae in Naenae, where his tangi is to be held.
A kaumatua of the marae and a close friend of the family, who declined to be named, said Mr Hadfield's partner was particularly distressed.
A Fenchurch Grove resident said he had spoken to Mr Hadfield on several occasions while out walking his dog. "I met him with his [partner] and kids and he seemed like a nice guy."
Neighbours said the family had not lived on the street for long, but were often seen out walking with their children.
Police have arrested two men, aged 22 and 20, and charged them with common assault but further charges are pending. They have been remanded in custody and are to reappear in court next month.
Police were still hunting for the weapon and asked witnesses to come forward.