July 25 (Reuters) - A raging wildfire has devastated the

western Canadian tourist town of Jasper, potentially destroying

up to 50% of structures, and firefighters were working on

Thursday to save as many buildings as possible, authorities

said.

Jasper is in the middle of mountainous Jasper National Park,

in the province of Alberta. The town and the park, which draw

more than 2 million tourists a year, were evacuated on Monday,

when officials estimated there were up to 10,000 people in the

town and a further 15,000 visitors in the park.

"There is no denying that this is the worst nightmare for

any community," Alberta premier Danielle Smith told reporters,

while choking back tears.

"We're seeing potentially 30% to 50% structural damage ...

that's going to be a significant rebuild," she said, adding the

fire was still out of control.

Parks Canada said there had been a "significant loss" of

buildings inside the town but added it could not give specific

details of the damage, or which areas had been hit and it urged

residents not to return.

Video from the town showed vehicles and entire blocks burned

to the ground, including a historic Anglican church.

Jasper resident Eva Korduliakova heard the news that her

home was burning from thousands of kilometers away Thursday

morning, while visiting family in the Czech Republic with her

seven-year-old son.

"I am single mum who became homeless and jobless overnight,"

she wrote in an email. "Our house is gone. I didn't get a chance

to grab any of my belongings."

Jasper mayor Richard Ireland said the town was beginning to

come to terms with "the devastating impact" of the fire.

"Last night's wildfires have simply ravaged our small

tight-knit mountain community, the destruction and the loss that

so many of our residents are facing simply defies description,"

he told a press conference, his voice breaking.

One major concern for responders is if the fire damages

the Trans Mountain oil pipeline, which can carry 890,000 barrels

per day (bpd) of oil from Edmonton to Vancouver.

"At this time there is no indication of damage to our

infrastructure, and the pipelines continue to operate safely,"

pipeline operator Trans Mountain said in a statement.

CN Rail said it suspended rail operations through

the town on Wednesday afternoon as the wildfire conditions

worsened.

The federal government and other cities in Alberta are

sending emergency crews. In addition, a total of 400

firefighters from Mexico, South Africa, Australia and New

Zealand are due to arrive in the coming days.

'WALL OF FLAMES'

There are currently 176 wildfires burning in Alberta, more

than 50 of which are out of control. Around 10 of those blazes

are close to the border with British Columbia, where there 423

wildfires burning and dozens of evacuation orders and alerts.

The federal government said in April that high temperatures

and tinder dry forests meant this could be a catastrophic year

for wildfires in Canada.

The Jasper fire was caused by a lightning strike on Monday

afternoon and fuelled by strong winds, according to Parks

Canada.

Flames from the blaze rose 100 meters high (3 feet), and

strong wind gusts on Wednesday afternoon pushed the fire 5

kilometers (3 miles) in less than 30 minutes, said Alberta

public safety minister Mike Ellis.

"Any firefighter will tell you there's little to nothing you

can do when you have a wall of flames coming at you like that,"

Ellis said.

Environment Canada is forecasting 10 mm (0.4 inches) to 20

mm of rain for Thursday, which might help firefighters.

The Jasper Park Lodge, one of the largest hotels in town,

said the fire had reached its grounds. The 400-room residence is

run by Fairmont, a group owned by France's Accor.

The Jasper fire could be one of the most damaging in

Alberta since a 2016 conflagration that hit the oil town of Fort

McMurray, forcing the evacuation of all 90,000 residents and

destroying 10% of all structures in the city.