The wife of the lone survivor of Tuesday's plane crash in northwestern Ontario that killed four people says it's remarkable he escaped the burning wreckage.

Tracy Shead told CBC News that her husband, Brian Shead, was sitting in the last row of the small plane en route to North Spirit Lake from Winnipeg.

The Piper PA-31 Navajo went down about 10 a.m. about a kilometre from the runway in the remote community.

Aboriginal Strategies statement The staff of Aboriginal Strategies is deeply feeling the loss of part of our family. Our president, Ben van Hoek and accountant Colette Eisinger died Tuesday morning, January 10, 2012, in a tragic plane crash in the community of North Spirit Lake First Nation. We grieve together with their families and extend our deepest condolences. Our sympathies also extend to the family of Martha Campbell and we extend our gratitude to the many North Spirit Lake community members that assisted with the rescue efforts and with communications with our office during this stressful time. Our condolences also to the family of the pilot and to the Keystone Air staff. We pray for a speedy recovery for our co‐worker, Brian Shead, the only survivor of the crash. — Lyndon Olfert, on behalf of the board, management and staff of Aboriginal Strategies

"I guess the tail broke off and he was able to crawl out," Tracy Shead said. "It's amazing. I'm just so happy he's alive."

The plane was on its landing approach when it slammed into a frozen lake and caught fire, said Peter Hildebrand of the Transportation Safety Board.

The cause of the crash isn't yet known, though there are reports of blizzard conditions at the time.

Four people on the plane — three passengers and the pilot — were killed.

Investigators arrive at crash site

Two Transportation Safety Board investigators arrived at North Spirit Lake on Wednesday afternoon to begin what Hildebrand conceded will be a challenging investigation.

"The wreckage is extensively damaged by fire and impact forces," Hildebrand told CBC News. "It's located in a very remote location, so we're really just going to have to resort to basic investigative techniques."

The investigators also hope to gain valuable information from Brian Shead and from North Spirit Lake residents who may have seen what happened as the aircraft approached the runway, Hildebrand said.

They couldn't reach the crash site earlier because of its remote location.

Tried to put out fire

Tracy Shead visited with Brian Tuesday night in Winnipeg's Health Sciences Centre, where he's in stable condition with injuries to his face and foot.

"It was amazing just to see him, and he's talking and he's coherent and he's alive," she said.

He is having a difficult time thinking about what happened, the loss of friends and colleagues, "and why he made it and the others couldn't," she said.

Tracy said Brian, despite being injured, tried to put out the fire in the plane by throwing snow on it.

"He was calling for help — he called everybody's name but nobody was responsive at that point. I don't know if they ever became responsive," she said.

"He said he walked around the plane and they had water bottles on the plane and he was using those to try and put out the fire, and then when those ran out, he got the cooler and filled that with snow and was trying to put out the fire, but it wasn't working. And then help came.

"It's, it's surreal, it really is. I think he was just running on adrenalin."

Worked for Winnipeg company

Brian and two of the other passengers worked for Aboriginal Strategies, a Winnipeg company that provides financial management services to First Nations.

David Harper, grand chief of Manitoba Keewatinowi Okimakanak, the agency representing northern Manitoba chiefs, said Ben van Hoek, a financial manager with Aboriginal Strategies, was among those killed.

North Spirit Lake is located in remote northwestern Ontario, near the Manitoba border. (CBC)

He described Van Hoek as a mentor in many remote communities.

"He was a man that would go to any length to help out and these are the communities that a lot of people never hear about — those are the communities he would go to."

Chief George Kemp, of the Berens River First Nation in Manitoba, praised van Hoek's commitment to those remote communities.

"He liked to go and see for himself. Being a manager, he could have sat back and and let other people go, but that wasn't his style. He liked to be involved and get to know people and so forth," Kemp said.

One of the other deceased passengers, Colette Eisinger, was originally from the Sagkeeng First Nation in Manitoba, though she was most recently living in Winnipeg.

Sagkeeng Chief Donovan Fontaine said the woman was related to two of his employees, and they're taking the news hard.

"She was well educated in finances, accountability, that's the work she did, so a big loss," Fontaine said.

Campbell 'helped a lot of people'

Aboriginal Services identified the third victim as Martha Campbell but did not say anything more.

She's listed as the health director on the Nishnawbe Aski Nation's website. The NAN is a political organization representing 49 First Nation communities across northern Ontario.

Peter Hildebrand of the Transportation Safety Board said the plane was on its landing approach when it slammed into a frozen lake and caught fire. (CBC)

However, she was not serving in that role anymore. Campbell had moved to Winnipeg four years ago but frequently returned to North Spirit Lake First Nation — one of the NAN communities — to help in the band office, according to North Spirit Lake Chief Rita Thompson.

The chief said everyone in the community knew Campbell was coming in on that flight, and everyone quickly realized that she was one of the dead.

"I think today's much worse than yesterday because now it has hit us, the full impact of what has just happened," Thompson said.

She wants to put together a trust fund for Campbell's family, noting that woman was the sole earner for her family because her husband, Galebius, is on kidney dialysis.

Galebius Campbell told CBC News he does not want to know details of the crash or what may have caused it.

"I don't ask any questions … so I'm just leaving it like that and forgive," he said Wednesday. "She went peacefully; that's what they told me."

Aunt's loss mourned

James Campbell, 29, said he was raised by his aunt Martha and now he cannot believe she's gone.

"I was shocked; I was sad at the same time. I was just crying," he said.

Campbell said he never worried about his wife flying regularly on small airplanes.

"She helped a lot of people. Even when we moved to Winnipeg she still goes to the reserve to work for the people," he said.

Grief counsellors are working with North Spirit Lake residents in the wake of the crash.

Representatives with NAN said the band council requested a crisis team as well as mental health support. A team of three is already in place and other support is on standby.

The name of the pilot has not been released. The plane was operated by Keystone Air Service Ltd., a charter airline based in St. Andrews, Man.

Federal investigators with the Transportation Safety Board will be at the crash scene on Wednesday.

They couldn't reach the crash site earlier because of its remote location.

Safety of airline questioned

Experts in the aviation world are questioning the safety record of Keystone Air.

Tuesday's crash is the airline's third in just over a decade.

Rob Seaman, a columnist for Wings magazine, said he wouldn't get on a Keystone plane.

"There's something not adding up here. No company should have that many incidents in that short a period of time," he said.

Keystone operates with one pilot, unlike the major commercial airlines. A two-pilot model is safer, Seaman said.

The Piper flight to North Spirit Lake did not carry a cockpit voice recorder or a flight data recorder, technology it was not required to have.

Airspace in the region is uncontrolled, so pilots have liberty on their landing approach, Hildebrand said.

The pilot was in communication with air controllers in Winnipeg after takeoff, but Hildebrand said he was not aware of any communications with the plane afterward.