
These incredible aerial shots show the sheer scale of a wildfire in the Alberta city of Fort McMurray that is set to become the costliest ever Canadian natural disaster for insurers.

The unchecked fire, which entered its fourth day on Wednesday, has prompted the full evacuation of Fort McMurray's 88,000 residents.

Now, a mandatory evacuation has been ordered for Anzac, Gregoire Lake Estates, and Fort McMurray First Nation. Alberta's Royal Canadian Mounted Police are going door-to-door warning residents that they need to leave immediately, RT.com reports.

Alberta declared a state of emergency on Wednesday afternoon for what was shaping up to be Canada's costliest natural disaster. Premier Rachel Notley said fire had destroyed or damaged an estimated 1,600 structures.

Flames are being kept from the downtown area thanks to the 'herculean' efforts of firefighters, said Scott Long, of the Alberta Emergency Management Agency. No injuries or fatalities have been reported.

Long added that there was a chance that 'a large portion of the town' would be lost, The Star reports.

Chief Darby Allen of the Fort McMurray fire department said: 'There are certainly areas within the city that have not been burned, but this fire will look for them and it will find them and it will want to take them.'

The fire appeared near the airport late on Wednesday. All commercial flights in and out of Fort McMurray have been suspended.

With 1,600 buildings destroyed and another 19,000 under threat, analysts and industry sources say the bill for insurers is expect to exceed over C$2 billion ($1.6 billion).

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An aerial shots show the sheer scale of a wildfire in the Alberta city of Fort McMurray that is set to become the costliest ever Canadian natural disaster for insurers

The unchecked fire, which entered its fourth day on Wednesday, has prompted the full evacuation of Fort McMurray's 88,000 residents

Alberta Premier Rachel Notley flew up to survey the situation, while officials in the evacuation center had to bolt to the south of the city as flames edged closer

The wildfire is seen moving towards the town of Anzac from Fort McMurray, Alberta. A mandatory evacuation has been ordered for Anzac, Gregoire Lake Estates, and Fort McMurray First Nation has been ordered

The bill for insurers is expected to be several times more than the C$700 million ($544 million) paid out for a wildfire in Slave Lake, Alberta, in 2011.

The fire in Slave Lake, a small town 155 miles northwest of the city of Edmonton, led to the destruction of 374 homes - less than a quarter of the number of structures already destroyed at Fort McMurray - and damaged another 52.

'If you're looking at four times that of Slave Lake you're getting to well over C$2 billion ($1.6 billion) so there is a possibility that this may become the biggest catastrophic claim in Canada,' said DBRS analyst Stewart McIlwraith.

The fire is also likely to exceed the C$1.9 billion in losses caused by the Alberta floods of 2013, which set the record for the costliest Canadian disaster.

Those losses were limited by the fact that many policies did not cover the type of flooding experienced.

Experts say in Fort McMurray insurance policies would likely cover all damage to property and belongings damaged by the wildfire

Wildfires had been threatening the remote city for days when flames nearly doubled in size, fueled by dry conditions blamed on global warming, forcing the evacuation of the entire city by Tuesday afternoon.

Weather conditions in the Fort McMurray area are making it more difficult for firefighters to control the terrible blaze

One Twitter user posted photographs of the terrifying scenes as he drove down the highway just yards from the inferno

Heavy smoke obscured the sky while the flames made the area glow red forcing authorities to evacuate more than 70,000 people

Smoke from wildfires near Fort McMurray, Alberta, Canada are shown in this composite satellite handout photo from NASA

The raging wildfire emptied Canada's main oil sands city, destroying entire neighborhoods of Fort McMurray, where officials warned Wednesday that all efforts to suppress the fire have failed

Flames are being kept from the downtown area thanks to the 'herculean'' efforts of firefighters, said Scott Long, of the Alberta Emergency Management Agency. No injuries or fatalities have been reported

The fire appeared near the airport late on Wednesday. All commercial flights in and out of Fort McMurray have been suspended

Alberta declared a state of emergency on Wednesday and Premier Rachel Notley said fire had destroyed or damaged 1,600 structures

The blaze effectively cut Fort McMurray in two late Tuesday, forcing about 10,000 north to the safety of oil sands work camps

Unseasonably hot temperatures combined with dry conditions have transformed the boreal forest in much of Alberta into a tinder box

Unseasonably hot temperatures combined with dry conditions have transformed the boreal forest in much of Alberta into a tinder box. Fort McMurray is surrounded by wilderness in the heart of Canada's oil sands - the third largest reserves of oil in the world behind Saudi Arabia and Venezuela.

Danielle Larivee, Alberta's minister of municipal affairs, said the fire is actively burning in residential areas. More than 250 firefighters are battling the blaze. Fatalities have been reported from a collision on a nearby highway but she was unaware if it was related to the evacuation or fire.

There were haunting images of scorched trucks, charred homes and telephone poles, burned out from the bottom up, hanging in the wires like little wooden crosses.

Alberta Premier Rachel Notley flew up to survey the situation, while officials in the evacuation center had to bolt to the south of the city as flames edged closer.

Notley tweeted pictures of the fire from above. 'The view from the air is heartbreaking,' she wrote.

The blaze effectively cut Fort McMurray in two late Tuesday, forcing about 10,000 north to the safety of oil sands work camps.

An evacuated resident puts gas in his car on his way out of Fort McMurray, Alberta, as a wildfire burns in the background

Fort McMurray is surrounded by wilderness in the heart of Canada's oil sands - the third largest reserves of oil in the world behind Saudi Arabia and Venezuela

Firefighters were working to protect critical infrastructure, including the only bridge across the Athabasca River and Highway 63, the only major route to the city in or out

The city's entire population was ordered to evacuate after an earlier order that had applied to almost 30,000 people, mostly on the city's south side

The province called in more reinforcements to Fort McMurray, including 100 more firefighters and a giant helicopter that can dump more than 2,000 liters (500 gallons) of water at a time. Above, a pilot flies bear the wildfires

The other 70,000 or so were sent streaming south in a bumper-to-bumper snake line of cars and trucks that stretched beyond the horizon down Highway 63. Some vehicles sat in ditches, the victims of engine trouble or a lack of gas.

Firefighters were working to protect critical infrastructure, including the only bridge across the Athabasca River and Highway 63, the only major route to the city in or out.

Notley called it the biggest evacuation in the history of the province. Federal Public Safety Minister Ralph Goodale called it one of the largest fire evacuations in Canadian history, if not the largest.

'It's a community of 88,000 people that's been totally evacuated,' Goodale said. 'This is going to take a while to recover.'

'While the full extent of the damage isn't yet known, we certainly do know that for those who have been affected this fire is absolutely devastating,' Canadian Prime Minister Pierre Trudeau told a news conference in Ottawa.

'It's a loss on a scale that is hard for many of us to imagine.'

Chief of Fort McMurray called it a 'nasty, ugly fire' that is showing no forgiveness.

'It's the worst day of my career. The people here are devastated, everyone's devastated, the community is going to be devastated. This is going to go on. This is going to take us awhile to come back from. But we'll come back.'

Resident Neil Scott told the BBC: 'It was something you'd see in a movie probably. I was stuck between a concrete barrier and the fire and I though 'You know what? I might not make it out'.

'There's whole neighbourhoods that are gone. A hotel burned down, a gas station exploded. One lady that I met she actually was sheltered behind like an electrical box when it actually exploded and she felt a shockwave.'

Firefighters had seemed to be making progress controlling the blaze, but the situation worsened quickly on Tuesday.

Evacuees from the Fort McMurray wildfire leave The Expo Centre after receiving supplies in Edmonton, Alberta, on Wednesday

Dan Crane and Elisha Car take refuge in a work truck after being evacuated from Fort McMurray, Alberta, Canada, on Wednesday

Fort McMurray residents sleep at a community centre in Anzac, Alberta, after residents were ordered to evacuate the city

Traffic lines the highway as residents leave Fort McMurray, Alberta, Canada, after the city's more than 80,000 residents were ordered to flee

The province called in more reinforcements to Fort McMurray, including 100 more firefighters and a giant helicopter that can dump more than 2,000 liters (500 gallons) of water at a time.

But while oil sands facilities are not in the fire's path, at least four companies have curbed activities to allow workers and others to get to safety. It was unclear what percentage of production had been affected by the fire.

The city's entire population was ordered to evacuate after an earlier order that had applied to almost 30,000 people, mostly on the city's south side, was extended as flames continued to make their way into the city on Tuesday.

Residents became panicked as flames jumped onto Highway 63, the only road out of the city.

The wildfire, whipped by unpredictable winds on a day of high temperatures, worsened dramatically in a short time and many residents had little notice to flee.

As many fled to oil sands workcamps to the north of the city, or south on the one clogged highway out of town, hundreds of dwellings furiously burned.

'I was panicking, to be honest with you, we could see the ash - a rain of ash, the cars were full of ashes,' said Fatima Mian, a single mother-of-three who raced to pick up her children from school before fleeing the city on Tuesday.

Smoke fills the air as people drive on a road in Fort McMurray, Alberta, Tuesday. 'When you leave ... it's an overwhelming feeling to think that you'll never see your house again,' one resident said

Students from Fort McMurray Composite High School are released early as wildfire burns nearby. The city was being emptied Tuesday due to the flames

Alberta Premier Rachel Notley said officials were doing all they could to ensure everyone's safety and said they were looking into the possibility of an airlift for residents with medical issues

This photo take through a car windshield shows smoke rising from a wildfire rages outside of Fort McMurray, Alberta, on Tuesday

Most oil sands projects are well north of the community, while the worst of the flames were on the city's south side. Pictured, smoke rises behind a gas station Tuesday

She found refuge in an oil workers' camp about an hour from the city.

Resident Breanna Schmidt added evacuating almost felt like 'an apocalypse.'

'We had to literally drive through smoke and fire, vehicles littered all over the sides of the road, and we had to drive as fast as we could and breathe as little as we could because the smoke was so intense and we could feel the heat from inside the vehicle,' she said.

Former National Hockey League player Doug Sulliman said he could see from his apartment balcony that both sides of the highway south were engulfed in flames and estimated hundreds of homes in the Beacon Hill suburb over the hill were destroyed.

'You could hear the pop, pop, pop because of the propane tanks. The fire was just consuming these houses. It just destroyed the whole community,' he said.

He said the highway later opened and it was bumper to bumper and said there were many cars on the side of the road because service stations were out of fuel.

'There was a Shell gas station that blew up and a Denny's next door. There was nothing but the foundation and it was still smoldering in flames,' he said.

But Fort McMurray was already crippled by a collapse in crude prices before flames raced into the once-booming city, burning hundreds of homes to the ground and chasing residents into bush camps for safety.

Dubbed Fort McMoney when its oilsands industry was flourishing and residents were among the wealthiest in Canada, the town had been hemorrhaging workers and wealth for 18 months before fires forced the evacuation of the city's 88,000 residents.

Surrounded by thick boreal forest and vast oil sands deposits, hundreds of kilometres from the nearest major city, Fort McMurray was deeply reliant on a single commodity.

Traffic is at a standstill on Highway 63 heading south as residents flee with wildfires burning in and around Fort McMurray, Alberta

Conservation officers haul supplies to the evacuation center in Anzac south of Fort McMurray, Alberta

Residents of Fort McMurray line up outside a grocery store in Anzac after they were ordered to be evacuated due to a raging wildfire

Volunteers stock shelves as they prepare for the residents of Fort McMurray displaced by a raging wildfire, in Anzac, Alberta

Alberta Premier Rachel Notley (pictured, speaking to reporters) flew up to survey the situation, while officials in the evacuation center had to bolt to the south of the city as flames edged closer.

Its population ballooned to over 120,000 in 2015, sparking housing shortages and skyrocketing prices, before a 70 per cent drop in oil prices last year slammed the door on growth, prompting the exodus of almost one-third of its inhabitants.

'Stores were closing, small businesses were closing. A year or two ago you could not get a seat in the restaurants, but the buying power was not there any more,' said Ria Dickason, a South African immigrant who has lived in Fort McMurray for 14 years and fled the fires on Tuesday.

'Everyone was concerned about it, because it impacted every single person. It doesn't matter what type of work you do because lots and lots and lots of people lost their jobs.'

Real estate websites are littered with listings for sprawling Fort McMurray homes with asking prices approaching C$1 million - double Canada's average home price - in neighborhoods that are now charred and smoldering amid Alberta's largest-ever evacuation for a fire.

'Fort McMurray was really the ground zero of all that was happening related to oil and gas,' said Sandeep Agrawal, urban studies and regional planning professor at the University of Alberta. 'When this bust happened, it was catastrophic in many ways.'

Mian, a realtor who has been trying to sell homes left vacant by the exodus, said she knows the city is vilified by environmentalists who blame the development of the oil sands for increasing greenhouse gases and climate change.

'Fort McMurray has a big stigma attached to it, but it's a work town, people come here to work and make money. We understand global warming and stuff but ... people do long shifts here to raise a family and support a family,' she added.

The whole city of Fort McMurray, Alberta, the gateway to Canada's oil sands region, is under a mandatory evacuation order because of an uncontrolled wildfire that is rapidly spreading, local authorities said

The photo on left, provided by Tyler Burgett, shows flames from a wildfire along Highway 63 in Fort McMurray, Alberta, Tuesday. Right, lines were long in the northbound lanes