Howard Rensler has lived close to forest fires before, but what he saw Tuesday will stay with him forever.

He and his wife spent much of the day at the MacDonald Island Park evacuation centre just outside downtown Fort McMurray.

By late afternoon, every residential area in the city of 60,000 was under evacuation order, with people forced to leave their homes as fire spread from the southeastern edge of the Alberta city, then moved rapidly west, devouring entire neighbourhoods.

Eventually, even the evacuation centre was evacuated, and the Rensler's took to the highway, headed south for Edmonton.

"We have passed all sorts of burnt and burning (buildings) right on the roadside of Highway 63," Rensler said Tuesday evening. "Including what was a Super 8 Motel and a Denny's restaurant. There are simply trees burning 10 feet of the highway."

Rensler used to live in Kelowna, B.C., so he has some experience with forest fires.

"What's happened this time is an order of magnitude greater than I've ever experienced," he said. "The fire actually came into town. There was an incredible amount of property damage to residences and businesses."

'I was panicking'

Dwight Howlett didn't think he would make it out the city alive.

Forced to leave his Gregoire mobile home, as Howlett made his way south from downtown flames began to lick at the side of his pickup truck.

"I was going up the hill, and the traffic was three cars wide, and by the time I got up the hill, I couldn't see anything," Howlett said. "There was just smoke everywhere. I was just following headlights.

"I was sitting in my car in the line-up, and I could feel the heat of fire all around me."

Gridlock traffic in ymm. Lots of sirens. Hot weather and wind has clearly whipped up fire <a href="https://t.co/KGIDrpxAZJ">pic.twitter.com/KGIDrpxAZJ</a> —@briarstewart

Low on fuel, Howlett decided he didn't have enough time to stop for supplies, and made a beeline for the south of the city.

"I was panicking. I really didn't know I was going to make it out of there. I was near tears."

With help from his sister, Howlett managed to get out of the city, but he is certain he will never see his home intact again.

"I was lucky to make it out when I did," he said from the safety of an Anzac evacuation centre.

Gas supplies run low

Danielle Lamoureux left work early and rushed home to Thickwood, where she and her husband grabbed their important papers, some cash and clothes. By the time they drove away, their whole neighbourhood was being evacuated.

"It hit me when I could see the highway," she said, "and on the other side I could see flames down by the road. That's when I got really nervous."

As they drove south out of the city, "there was fire on my left and fire on my right. It was pretty terrifying," she said.

Chaos ruled the day across the city as residents tried to escape the flames.

On Highway 63, near an industrial area, flames burned trees right next to the road.

Over the sound of sirens, people could hear the constant pop, pop, pop of exploding propane tanks.

Supplies of gasoline soon ran short, making the trip out of town even more frantic.

For Ian Seggie, the scene was surreal.

"We are heading north, we're getting out," he told CBC News.

"I've offered rides to people that don't have full gas tanks. I was fortunate enough to fuel up yesterday, so I'm going to be making some pit stops along the way to pick people up.

"I've seen one gentleman walking the highway with his suitcase already."

A Timberlea resident, Seggie had been watching the flames from his balcony for the last two days. He said it was strangely clear and calm Tuesday morning, but the situation soon changed.

"Within two hours this afternoon the wind shifted, and that was it," he said. "You could just see it coming.

"I've never seen anything like this … but this is really just unreal. I've never seen anything like this. It's right on our doorstep."