The "horrific" wildfire that ripped through the Fort McMurray region in May will cost insurance companies an estimated $3.58-billion, making it by far the costliest natural disaster for Canadian insurers.

The total loss estimate, based on a survey of insurers, is more than twice the figure of the southern Alberta floods three years ago – what previously had been the costliest natural disaster on record for the country's insurance industry.

And unlike the 2013 calamity, the costs associated with the massive wildfire's destruction of 2,400 Fort McMurray homes, and damage to many others, will be largely borne by insurance companies, said the Insurance Bureau of Canada.

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"While this event is largely an insured one, the numbers fall well short of measuring the real tragedy of this wildfire – one that has taken an immense toll on thousands of individuals and families," IBC vice-president Bill Adams said Thursday.

Mr. Adams called the wildfire "one of most horrific and damaging natural disasters in Canadian history."

Catastrophe Indices and Quantification Inc., the company that surveyed insurance companies and compiled the total losses, said 62 per cent of the costs are related to personal property damages, while 33 per cent are attached to commercial property and five per cent are related to auto damage.

As the insurance industry continues to work through tens of thousands of claims, the estimate adds to Alberta's ledger of costly catastrophes. The bureau said seven of the 10 costliest insured natural disasters in Canadian history have taken place in the province, which has "volatile weather," a fast-growing population and an abundance of expensive properties.

"But ultimately, what we are seeing is that our climate is changing. And the long-term trends are directly the result of some of those dynamics," Mr. Adams said, adding that the insurance industry, governments and society as a whole need to do much more to prevent such costly disasters, including changing the way homes are built in fire- and flood-prone areas.

"Historically, we have not done that well in Canada, and perhaps less so in Alberta. And unfortunately we're living with the consequences now."

This year's fire forced the mandatory evacuation of Fort McMurray on May 3. The blaze destroyed about 1,820 single-family homes, as well as another 600 condo and apartment units, according to the bureau.

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The evacuation order was lifted more than a month ago and people have been returning to the community. However, it was only this week that the Alberta government deemed the wildfire under control.

As a result of the fire, there are more than 27,000 personal property claims, at an average amount of $81,000. There are more than 5,000 commercial insurance claims at an average $250,000 a claim.

But for Canada's insurance industry, this disaster stands in contrast from the 2013 southern Alberta floods. Those floods cost a total of $6-billion. But because overland flooding has not traditionally been included in insurance policies, there was only $1.7-billion in insurance claims (largely for sewer backup). The provincial and federal governments, as well as individuals, paid more than $4-billion for uninsured losses.

The total bill for this year's wildfire is still in question. Other costs related to the fire, including firefighting and evacuee relief payments, will come from the public purse. Ottawa, and the government of Alberta, will be on the hook for hundreds of millions of dollars, or more.

For its part, the province said Thursday it's still too early to know the total cost of this wildfire for government. The federal government has already said would release the first $300-million of funds through its Disaster Financial Assistance Arrangements program this month. The program provides cost-shared financial assistance for large-scale disaster events where costs are above what individual provinces or territories could reasonably be expected to bear on their own.

Early on, the Fort McMurray wildfire prompted the rating agency Standard & Poor's to predict that insurance premiums in Alberta will rise, especially following the trend of costly disasters in the province. However, Mr. Adams said no single event, even one of the magnitude of the Fort McMurray wildfire, will in itself trigger premium increases.

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"The industry really looks at long-term trends in claims as an indicator of ultimately where premiums will go," he said.

"What impact this will have will be determined at a later date, by individual insurers."

The industry group said it could not provide details on whether Albertans as a whole currently pay more for home insurance premiums, but said insurers make decisions about rates based on more localized risks – including whether homeowners live in areas prone to hail or forest fires.