A former Oamaru man stood and watched as tens of thousands of Fort McMurray residents fled an out-of-control wildfire burning the city in northern Alberta, Canada.

Craig Rowland, a Waitaki Boys' High School old boy, and his family were forced to wait about an hour at home - under a mandatory evacuation order - as smoke filled the sky.

"I could see the tops of the flames, just over the tops of the houses from where we were," he said, speaking from the highway with his family.

"You know what, it was really quiet. I couldn't believe it. We were all just standing there looking at the sky, big billows of smoke coming from the houses just over the road. That's what it looked like anyway.


"It was a crazy sensation. It was calm. Everyone was just sitting there ... and we would sort of talk to each other and we were like 'We've got to go but we can only go as far as the end of the street'."

Mr Rowland, his wife Lara, their 10-week-old son Eddie, 20-month-old son Jack and their Scottish terrier had been driving for three and a-half hours but had travelled only 50km north of the Canadian city.

"I don't think I've got over 20kmh yet."

The 2650ha fire was discovered three days earlier but shifted aggressively with the wind yesterday morning (NZ time). It quickly doubled in size and breached city limits.

Last night, Canadian media reported 35,000 people had fled the city, heading south towards the provincial capital, Edmonton, 430km away, and 17,000 people had fled north, heading to work camps for the oil sands which support the city.

All 88,000 residents of Fort McMurray were forced from their homes as the fire burned down 1600 structures had the potential to destroy much of the town, authorities said.

Mr and Mrs Rowland both work for Canadian Natural Resources Ltd in Alberta's oil sands and they were among those headed to a work camp. He did not know what to expect when he reached the oil sands work camp.

On the way north, many people had pulled over to spend the night in their cars, hoping to return to the city, he said.

"There are vehicles on the side of the road just the whole way up.''

Mr Rowland said when he was working the night shift the day before, he had not been worried about the fire.

"The updates we were getting was things were going to be calm, things were under control, and not to worry ... and within 12 hours everything's just gone. The wind just switched south and pushed everything into town.

"[When] I woke at about 5am today, things were good,''

But when Mr Rowland received the evacuation order he "threw everything into the car''.

"I grabbed the dog, some clothes for the boys. We had bottles of water and stuff, so I managed to throw all that in. I filled up a suitcase really quick with a passport, wallet, some clothes for us and that was it. We were out of there.''

The Rowlands live on the north side of town. On the south side, things were "crazy''. Mr Rowland had spoken to a friend whose house had burned down, "neighbours' propane (lpg) tanks were exploding before they could get out of town''.

"The way the city is built, you kind of come down into a ravine where the river goes through and I think the fire has just tracked all the way through there and turned it into a bowl of wind and flames,'' he said.

"I'm hoping the house is still there.''