The “inconsolable” sole survivor of a New Zealand car crash which killed his wife and granddaughter has spoken of the moments leading up to the tragic smash.

Michel Eades, known to friends as Geoff, was driving his wife Sera, three-year-old Iva Harper and cousin Valerie Bryan to visit his sick mother in hospital when the family hit a power pole which crushed their car just two kilometres from where they were staying.

In an interview with a New Zealand TV station, Mr Eades told how he fell asleep at the wheel before the car crash. In the heartbreaking interview, broadcast on Sky News, he said his granddaughter, his wife Sera and her cousin "knew nothing about it" and "had a peaceful" death.

Speaking from his hospital bed last week, through his brother John McCombe, Mr Eades said the family had been taking the bus every day but on Wednesday they decided to drive - a decision which has left Mr Eades “inconsolable.”

Mr McCombe said: “On the three previous days we had taken them or they had caught the bus, but yesterday [Wednesday], my elderly father said, 'Why don't you take my car?' So they spent the day visiting the hospital, but the combination of jet lag, no sleep and stress came together. They hit the pole. No-one else was involved."

Mr Eades, a software expert, is still in hospital recovering with broken ribs and a broken ankle.

Paramedics and hospital staff battled to save little Iva’s life for hours before pronouncing her dead late in the evening.

Through his brother Mr Eades said he was “stunned by the dedication of emergency services. They worked almost beyond belief to try to save that little girl's life.”

Police said tiredness was probably the cause of the accident with an impact speed of between 35kmh and 40kmh.

New Zealand Detective Sergeant Andrew Fabish said the case was the most tragic he had seen in his career.

He said: “It's absolutely horrible. Good people obeying all the rules. They were wearing seatbelts, but the lamp-post doesn't move and a car weighs over a tonne. That's a lot of force.”

The couple and Mrs Bryan had taken Iva, who was due to start nursery next week, on holiday to meet extended family.