The death toll in the Victorian bushfires climbed last night to 84, including four children, with warnings that more deaths are likely to be confirmed as emergency crews work their way through devastated towns and properties.
The scale of the human toll, with more than 700 homes destroyed, tens of thousands of livestock lost, massive damage to roads and communications - including landline and mobile services in areas where they were crucial to survival - places the weekend's holocaust among Australia's worst.
In 1926 fires in the Dandenongs, Gippsland and Warburton in Victoria killed 91 people, 71 died in the state's "Black Friday" of 1939, and 75 perished in Victoria and South Australia in the Ash Wednesday infernos of 1983.
"Hell in all its fury has visited the good people of Victoria in the last 24 hours and many good people now lie dead, many others lie injured," Prime Minister Kevin Rudd said.
"This is an appalling tragedy for Victoria but because of that, it's an appalling tragedy for the nation, and Australia the country stands behind Victoria at this awful time."
As hospital workers likened the rush of burns victims to survivors of the Bali bombings, fire authorities told people still facing vast, wind-driven walls of flame that engines and rescue vehicles might not be able to reach them in time.
With hundreds of thousands of hectares of the state already incinerated, towns and homes were last night still under threat from bushfires raging towards them, and areas already razed are likely to remain at risk from embers and hot, windy days.
At least some of the fires are believed to be the work of arsonists, including some who authorities believe re-lit outbreaks contained by volunteer crews working in searing winds and temperatures above 40C.
"To think you could do that in those conditions when you knew that any fire you lit had the potential to cause severe losses and death, I think that's something that is just appalling," Victorian Emergency Services Minister Bob Cameron said.
Police said suspects could be charged with murder.
To the north, New South Wales is now feeling the brutal onslaught of a heatwave that yesterday pushed temperatures into the 40s.
Fire crews, backed by bulldozers and aircraft, yesterday fought 60 bushfires, 10 of them raging out of control.
"The prospect of containing these fires is remote at best," Rural Fire Services Commissioner Shane Fitzsimmons told ABC television.
On Saturday, a 3-year-old boy died in a house fire in Muswellbrook in the Hunter Valley.
New South Wales and South Australia have both sent units to help Victorian firefighters, but South Australian authorities warned that their crews would be pulled back by the end of the week as their state returned to a heatwave threatening fires of similar magnitude.
Mr Rudd has provided a A$10 million relief fund and ordered Army bulldozers in to help contain fires continuing to threaten Victoria.
The speed and ferocity of the weekend's fires has shaken Australia.
"Nature gave Victoria a beating of unimaginable proportions," state Emergency Services Commissioner Bruce Esplin told ABC radio.
The disaster had become inevitable as one of the worst heatwaves in Australian history, following a decade of drought, punished the state with a record run of temperatures of more than 40C.
Dozens of fires broke out, but the worst were concentrated in the alpine region to the northeast of Melbourne, around Bendigo, and in Gippsland, already hammered by last week's fires in the Latrobe Valley.
Most of the deaths confirmed so far were in towns clustered around alpine state forests, and to the southeast of Melbourne.
The scenes were horrific.
The Melbourne Herald Sun's Terry Brown reported seeing two locals in Marysville, northwest of Melbourne, gently lift the corner of a grey army blanket lying on the road more than 15 hours after the fires went through.
The whole town is a scene of almost unimaginable destruction, but their faces are more desolate, Brown writes.
Marysville is a close-knit town. Everyone knows everyone, but the two locals can't tell who it is they have found. They only know that it seems to be a young girl.
Raylene Kincaide fled from Narbethong, a town near Marysville, which was almost totally burned to the ground.
"Everyone we know has lost everything they had," she told ABC radio.
"I've been in Ash Wednesday, but this is probably worse.
"It's just devastating...Our little town had gone 20 minutes after we left.
"Probably 95 per cent of the houses are gone."
The Yea recreation reserve has been transformed into a makeshift refuge for hundreds of people, mostly from Flowerdale and Kinglake.
Those who speak about what they have seen do so in hushed tones because too many of the people around them are grieving or waiting for news of loved ones.
"One of our friends, her husband's still missing. He turned back to help try and save their house," Tina Chapman, of Flowerdale, said.
"She hasn't heard from him since," her partner Alan Phillips added.
The pair and Ms Chapman's daughter Monique, 18, have lost their rented home and all of their possessions. They have no insurance.
At Melbourne's Alfred Hospital, emergency physician John Coleridge said the 18 people he was treating for burns yesterday - eight of them in intensive care - would not be the only victims.
"There are apparently cars along the roadside just abandoned," he told ABC radio.
"Unfortunately they'll probably find many more people, many of whom may not survive."