An almost stationary high-pressure system had established itself over the Tasman Sea, sucking in intensely hot air from the red centre. Huge bushfires flared as temperature records were set.

In Victoria, where 71 people lost their lives, the conflagrations became known as Black Friday.

But the effects were felt in NSW too. For the people of the historic Hunter Valley river port of Seaham, January 14, 1939, became the day their town died.

Toby Ralston, then aged 10, was on holiday with his parents and sister in Forster that day. He remembers watching the smoke rising above Tuncurry on the opposite side of Myall Lake.

Unbeknown to them, their magnificent homestead in Seaham, Porphyry, would also go up in flames along with the Presbyterian Church, the school, schoolhouse, and another 19th century homestead.

Matthew Endacott, 18, who has been researching the Seaham fire and its aftermath, says the destruction of Porphyry was described at the time as "a national loss".

It was a handsome, stone-built, symmetrical house, with two wings either side of a recessed veranda originally the homestead of a highly regarded vineyard which had closed in World War I.

"There isn't even a decent photograph of this beautiful old home," Mr Endacott said.

The only part of the original property that survives is the winery's old still house.

"There was no-one here to fight the fire," Mr Ralston explains.

During the 19th century, Seaham's position on the Williams River made it an important inland port. But when the North Coast railway was built, bypassing Seaham, trade began to wither.

However it was the events of January 14, 1939, that turned Seaham's hopes of revival to ashes.

"Temperatures peaked at 49.4 in Singleton," Mr Endacott said.

"A fire that had been burning for several days near Paterson was being fanned by high winds towards Seaham.

"The decision was made to evacuate women and children. Many crossed the Williams River into East Seaham by punt."

At one 19th century homestead, the McDonald family submerged their children in a dam.

"The Newcastle Sun reported that the last message received by the police at Newcastle from the postmaster before the town was isolated was: 'I will have to run now. Fire is all around me!'," Mr Endacott said.

Amazingly, no one died. Nor were any cattle lost. The chief victim was Seaham itself, which became a ghost town until the 1980s development of Brandy Hill.

Even Mr Ralston's father took a decade to build a replacement homestead at Porphyry.

"So much was destroyed in the fire, Seaham's story is almost completely the product of oral history," Mr Endacott said. "You could be forgiven for thinking none of it ever happened." SMH