UPDATE: AN ENTHUSIASTIC 19-year-old has been named as one of two firefighters tragically killed while battling an alpine bushfire yesterday.

Katie Peters, from Tallandoon, and a 29-year-old man from Corryong died after a tree fell on their vehicle as they fought the edge of the 27,000ha Harrietville blaze.

Ms Peters had spent two seasons working for the Department of Sustainability and Environment in what was her first paid job.

DSE Chief Fire Officer Alan Goodwin said she would be "sadly missed by us all".

"Katie was always prepared to have a go and was the first one to put up her hand to drive a tanker or use a chainsaw," Mr Goodwin said.

"She made time for everyone. She loved working with her mates and was incredibly down to earth and loved by everyone that she worked with."

Mr Goodwin said the teenager loved animals and hoped to become a vet.

A statement from Ms Peters' family described her as a "farm girl".

It said she had grown up on a dairy farm and after her seasonal employment had planned to study science at Geelong's Deakin University.

"Her family remembers even from a young age having to call her in from the bush at dusk to return home for dinner. She had been in the bush riding her horse, often with her dog and cat in tow," it reads.

"Our family, Katie's partner, friends and work mates are united in grief as we try to come to terms with our loss.

"We thank everyone for their heartfelt wishes and messages of condolences, but ask that our privacy be repsected during this difficult time."

The 29-year-old man's name has not been released as his family is still being informed of his death.

"The death of any firefighter is tragic," Mr Goodwin said. "To lose young, dedicated people out there doing their jobs is especially so."

"Any death is unacceptable and I would like to personally extend my sympathies and the sympathies of DSE to both family and friends. Our thoughts and support are with them."

WorkSafe and Victoria Police are investigating the incident, which occurred yesterday at about 3.30pm.

Mr Goodwin said the pair was working on Pheasant Creek Track in a remote part of the alpine blaze, 170km north-east of Melbourne.

"They were out there as part of a taskforce, so multiple vehicles working in tandem … [they were] actually fighting the edge of the fire," he said.

They were believed to have been in a remote fire-fighting 4WD when the tree fell.

Fire Services Commissioner Craig Lapsley said it was a "hollow feeling" and a "significant loss for Victoria".

He said the DSE and other authorities would assist in the investigation.

"We need to reflect and learn whether this is something we can do better," Mr Lapsley said.

"We believe we've got good systems of safety in this state … it's an inherently dangerous role and we'll continue to ensure that safety is at the front of all of our firefighters in terms of what they do and how they do it."

Flags are being flown at half-mast on Victorian government buildings today and Premier Ted Baillieu said his thoughts were with the families of both firefighters.

“The tragic loss of these two firefighters will affect all those who have been fighting these fires and protecting Victorian communities,” Mr Baillieu said.

Australian Workers Union Victorian secretary Cesar Melhem said the two firefighters were heroes.

"These DSE firefighters work in the most horrific conditions imaginable, away from the big centres, out in the bush, and with very little recognition for their heroic contribution to this state," Mr Melhem said in a statement.

"They have died heroes, which will be small comfort to those that grieve for them."