(Adds Trudeau remarks at news conference, estimate of insurance cost)
By Ernest Scheyder
BONNYVILLE, Alberta, May 13 (Reuters) - Canadian Prime Minister Justin Trudeau praised firefighters on Friday for defending the energy hub of Fort McMurray and promised the federal government would pour money in to its recovery.
Trudeau toured the town in a military helicopter and saw a patchwork of neighborhoods destroyed by an inferno that forced the evacuation of all 88,000 inhabitants. Some homes still stood, while others had burned to their foundations.
The inferno closed the extensive oil sands operations near the town and the effort to restart them is progressing slowly. The wildfire knocked out nearly half, or 1.07 million barrels per day (bpd), of Alberta's oil sands capacity.
The blaze could cost insurers as much as C$6 billion ($4.7 billion), making it by far the most expensive Canadian natural disaster, according to ratings agency DBRS.
"To the people of Fort McMurray: Know that even though things may look difficult and uncertain and at times perhaps almost hopeless, know that you are not alone. Canadians are standing with you," said Trudeau.
"There will be significant federal monies invested in that community as we rebuild," he told a news conference in the provincial capital Edmonton.
Ottawa runs a fund to help provinces recover from disasters and could end up paying 90 percent of all eligible costs. Trudeau said the government would try to ensure the money was paid out more quickly than usual but gave no details.
After the aerial tour, he was briefed on progress fighting the fire, which has moved east of Fort McMurray into less inhabited areas, and praised emergency officials for their "valor and courage" in preserving much of the town.
"The work you did to save so much of this community, to save so much of this city and its downtown core ... was unbelievable," he said.
Trudeau has faced criticism in Alberta, a province that does not usually vote for his party, for waiting more than a week to survey the damage. He initially stressed he did not want his visit to interfere with firefighting efforts.
"I think it's a good thing he's coming," said Fort McMurray housekeeper Maureen Pearce at a supply center for evacuees in Lac La Biche, Alberta. "I hope he provides more aid."
Many of the evacuees are living in temporary accommodation across the province, while authorities work to restore power, gas, water and communications.
Local officials say it will be 10 days before they can even produce a plan for resettlement, much less allow people to return to a place where small fires are still erupting.
Rebuilding Fort McMurray "is the work of years," Alberta Premier Rachel Notley told the news conference.
Evacuees are collecting Alberta debit cards loaded with C$1,250 per adult and C$500 per dependent, as well as Canadian Red Cross aid of C$600 for each adult and C$300 for each child.
Pearce, who believes both her home and the hotel where she works survived the fire, said the emergency funds are helpful.
"But if we're going to be out of our homes for a month, we'll need more," she added.
The fire on Friday was 12 km (7.5 miles) from ConocoPhillips' Surmont oil sands site, which is 63 km (39 miles) southeast of Fort McMurray, and it had not advanced since Thursday morning, spokesman Rob Evans said. He said operations would be on hold until Alberta allowed people to stay overnight at Surmont's camp.
The inferno is a blow to Alberta's economy, which was already reeling from collapsing oil prices. But even so, portfolio managers see value in Alberta's government bonds, anticipating the province will rebound.
Four major oil firms operating in the area around Fort McMurray have declared force majeure, a contract clause to remove liability for unavoidable catastrophes.
The fire spans 241,000 hectares (596,000 acres), growing much more slowly than before.
$1=$1.29 Canadian With additional reporting by Nia Williams in Calgary, Liz Hampton in Houston, Matt Scuffham in Toronto and David Ljunggren in Ottawa; Writing by Rod Nickel and David Ljunggren; Editing by Cynthia Osterman