Mr Fleet said the not-very-mobile Mr Harrison tried to get out of the house and had made it across the dining room to a ranch slider where he was found not long after by two passersby.
He had burns to 60 per cent of his body.
Local builder Josh Judd told the Herald he was on his way to play tennis when he saw smoke and flames coming from Mr Harrison's house.
He had known Mr Harrison for years and would often drop off fish to him after a day out on his boat.
"I jumped out of the truck and I asked someone if he was all right and where was he, and they said they didn't know, so I thought he must still be in the house. I started running up the stairs and there was this guy up there yelling 'he's here, he's here'."
Upstairs was another local, Taf Kennings, who with Mr Judd found Mr Harrison covered in curtains he had pulled down as he tried to leave through the ranch slider on the second floor.
The pair grabbed Mr Harrison as fire and smoke engulfed the house, making it difficult to see or breathe.
As they took him from the house, two Tauranga Boys High students ran to their aid and helped Mr Harrison on to the lawn at the front of the house where a midwife was waiting with towels and oxygen.
Mr Harrison was airlifted to Middlemore Hospital but died yesterday from his injuries.
His close friend of 28 years, Pippa Grieves, was with him when he passed away. She said he was a runner and had fixed trucks and radios for the 25th Battalion during World War II.
After the war he returned to Europe for about four years to help with its reconstruction and met his wife Rosita, who later returned with him to New Zealand.
The couple settled in Whangamata in the 1960s. They had no children. Rosita died about six years ago.
Ms Grieves said Mr Harrison worked for TV manufacturer Pye and helped build New Zealand's first colour television set. He was fluent in Italian, Arabic and Hebrew and was learning Maori.
Mr Fleet said the tragic incident should be a reminder not to leave food cooking unattended and for people to ensure they had smoke alarms.