Jasper wildfire: 'Heartbreaking' damage as Canadian Armed Forces ordered to respond to Alberta blazes

Prime Minister Justin Trudeau authorized the Canadian Armed Forces to respond on Thursday to wildfires raging in Alberta.

Trudeau said he was sending "resources, evacuations support, and more emergency wildfire resources to the province immediately -- and we're coordinating firefighting and airlift assistance."

More than 400 firefighters from Australia, New Zealand, Mexico and South Africa are also on their way to help fight the wildfires in Alberta, he said.

"Alberta, we're with you," Trudeau said in a social media post.

The western Canadian tourist town of Jasper and Jasper National Park in Alberta have closed and were evacuated due to wildfires in the park, the largest national park in the Canadian Rockies.

Since two wildfires were initially reported on Monday near Jasper, they have merged into one and the wildfire situation "remains out of control," Jasper National Park said Thursday.

The fire reached the town of Jasper on Wednesday evening, the park said, resulting in "significant loss."

"Today has been an exceptionally difficult day for Jasperites, incident personnel, and everyone who loves Jasper," Jasper National Park said in an update Wednesday night. "As the pictures and videos circulating online show, significant loss has occurred within the townsite."

Jasper Mayor Richard Ireland said the town has been "ravaged" by wildfire. There could potentially be 30-50% structural damage in Jasper, according to Alberta Premier Danielle Smith.

"We don't know particularly which structures have been have been damaged and which ones have been destroyed," Smith said during an update on Thursday. "But that's going to be a significant rebuild and significant displacement for a long period of time."

Firefighters were working to save as many buildings as possible and protect critical infrastructure.

"As the heartbreaking images from Jasper emerge, I want to thank the brave first responders who are in Alberta right now, fighting to save every home and every community they can," Trudeau said Thursday.

Jasper National Park said a detailed damage assessment will take time to complete, but that "it is clear that some homes and businesses have been lost."

"The most significant structural damage is concentrated on the west side of town, southwest of Miette Avenue," the park said in an update Thursday afternoon. "Firefighting efforts have prevented significant damage to much of the infrastructure in the east end of town. Our priority remains protecting structures that have not yet been impacted by fire."

All critical infrastructure in Jasper was protected, including the hospital, emergency services building, the elementary and junior/senior schools and wastewater treatment plant, the park said.

There have been no reported injuries due to the wildfire, Jasper National Park said in an update Thursday morning.

More than 25,000 people were ordered to evacuate from the park and areas nearby this week due to the wildfires, officials said.

The evacuation impacted 15,000 people who were visiting and staying in the park when the order was issued, as well as about 10,000 people in the town of Jasper, including seasonal workers, according to the Alberta Emergency Management Agency.

"The Town of Jasper and Parks Canada's priority is the safety of our staff, residents and visitors," Jasper National Park said in a statement on Tuesday. "We acknowledge this is a stressful time and appreciate patience as this is an evolving and complex situation."

Reservations through Aug. 6 in Jasper National Park have been canceled. A reopening date has not yet been announced.

Alberta is experiencing "extreme wildfire conditions," with more than 170 wildfires burning across the province, according to the government of Alberta.

ABC News' Morgan Winsor contributed to this report.