"She was born in Kaikoura and has a family plot there," he said.
Morton told the Weekend Herald the couple ran for the door when the quake struck.
"I could feel her hitting my back. Then some bolts holding the log cabin down broke and the cabin moved very sharply and we both hit the ground hard.
"I could not find her and was yelling out with no reply."
He had to shine his car's headlights on the house to find her. Despite CPR and help from others she was unable to be revived.
It was 14 hours before a helicopter arrived to take Mackinnon's body to Christchurch. Morton stayed by her side the whole time.
"It was terrible. I've never, ever felt so helpless and alone in my life. It was pitch dark, the house was gone, it was still shaking and she was dead in my arms."
Mackinnon's family asked for privacy for the funeral.