Other buildings around it - old and new - survived the same forces with little or no structural damage, but the club interior collapsed as if hit by a bomb.

The iconic images of ant-like rescue workers, amidst massive slabs of twisted and broken concrete and tangled steel reinforcing rods, distilled the complexity of the Newcastle earthquake into one unforgettable and universal symbol.

Questions about why the club fell in so dramatically would be asked soon enough, but in the immediate aftermath of the quake, the focus of everyone outside was on saving those trapped inside.

Wayne Dean, who was secretary-manager of the club at the time, said on the 20^th anniversary that he briefly thought one of the trucks bringing sound equipment for that night's Crowded House concert had crashed.

"The whole building shuddered and in moments I knew it was more than a truck as a cascading movement followed. The noise was incredible, deafening. I stood up and tried to walk but the floor was swaying so much I couldn't hardly keep my feet. The lights went out and alarms started going off. It was obvious the entire building was collapsing."

The Newcastle earthquake 30 years later: The seismic shock that shook Newcastle to its core

Dean's office was protected by two sets of staircases.

"As I was leaving my office the wall opened up in front of me and vanished into a black abyss," he said.

He heard people screaming.

"There was a wave of dust that followed and for a time I couldn't see anything."

As devastating as the club collapse was, it is also remarkable that only nine people died among the 300 who were in the building at the time.

Rows of ambulances lined up quickly against the club ferried those who needed treatment to hospital, but a remarkable number were able to walk out unaided, or with scratches and bumps that were tended in the treatment tents that sprang up on the King Street median strip.

With the police and the army having barricaded much of the city, there were very few general onlookers. Everyone had a job to do. But even so, there would be a communal holding of breath that spread from the entrance out, each time a rescue crew emerged with a stretcher. And a scrum on the other side of King Street, late in the afternoon, when prime minister Bob Hawke spoke of what he'd seen after flying in from Kirribilli House.

Coroner Kevin Waller handed down his findings on the earthquake in July 1990, but while a visiting New Zealand earthquake expert believed the western wall of the club had failed, allowing the the various storeys to cascade into each other and break apart into the basement car park, Waller made no formal finding on why the building had suffered so badly.

University of Newcastle civil engineer Professor Rob Melchers, who gave evidence at the inquest and initially agreed with the "western wall" explanation, was commissioned two years later to write an expert report for a court case over the collapse.

For "legal reasons", his findings were not made public until the earthquake's 20^th anniversary, when the Herald first reported his new view of the club's collapse.

As a keynote speaker at an Australian Earthquake Engineers Society conference held in Newcastle last month, Melchers looked again at the quake in a paper called The Newcastle Workers Club in retrospect - what can we still learn?

He says that despite the overall amount of damage caused by the quake, very few buildings collapsed or suffered structurally to any serious degree.

"The case that stood out was the Newcastle Workers Club," Melchers said.

He said that in 1992 he had "immersed" himself in the available evidence and concluded that two supporting columns inside the building, C14 and C17, "exploded" as the earthquake's wave of force surged through the building. Both should have been larger than they were, and were too small to hold the 16 reinforcing rods that each were specified to contain. Instead, they were poured with four rods each.

"How these 16 bars were supposed to fit inside the smaller . . . columns was not clear . . . " Melchers said.

"Once the inconsistencies between the reinforcement schedules, the sizes of the column cross-sections and the sizes of the corresponding footings were recognised, it was relatively straight-forward to develop the likely sequence of a very rapid 'progressive collapse' of most of the west wall.

"While superficially the workers club failure was the result of the occurrence of the Newcastle earthquake, the analysis of the evidence suggests strongly that it is more realistic to consider the earthquake ground motions as simply 'the straw that broke the camel's back'."

In 2009, he said that if the under-strength columns had been properly reinforced, it was unlikely the building would have failed in the quake, and that the building "could have been pushed close to its limits even without an earthquake simply by being filled with a large number of people".

The collapse of the workers club led to a tangle of law suits that took at least eight years to sort out. At one stage, the club and Newcastle council were suing the architect, the builder and an engineer, as well as taking action against each other. The council eventually settled out of court with the club and its insurer, Zurich, agreeing to a reported $8.5-million settlement it believed would be covered by its insurer, GIO. But GIO denied liability, and the council would have to go all the way to the High Court to secure a $10-million payment to replace the money it had said had been paid out of council reserves.

But all of this was well into the future as the walking wounded found themselves out on the footpath outside the club, and the wail of sirens pierced the the still, summer air as the enormity of the damage became increasingly apparent.

Police rescue, fire offices, ambulance officers and paramedics, doctors, nurses, SES members and volunteers from the public were pressed into action at the club.

Captured in a series of images that have come to symbolise the quake, teams of rescue workers made their way deep inside the collapsed building, confronting scenes of terrible carnage inside the poker machine room, especially, where the living and the dead were thrown about in contorted confusion, many of them pinned by fallen concrete and toppled poker machines, and surrounded by a sea of coins.

As a club worker said outside the building that day: "The auditorium floor went through the poker machine floor, which went through the car park, which went through the basement."

Thirty years later, former club workers still grieve for those who did not survive. The people who worked in those hellish conditions on the day can still recount minute details of the lengths they went to in looking for, and bringing out, the living, and the dead. Compare their recollections with the things they told the media in the hours and days and weeks after the quake, and the accounts have grown little, if any, in the frequent retelling. Things were so extraordinary to begin with, there has been no need to exaggerate.

Perhaps it's only human nature, but some of the veterans of the three main services, the police, the ambulance and the fire brigades, are still fighting their corners when it comes to the way they were deployed at the club. Fire officers, especially, were aggrieved at being "under-used" at the club, and coroner Waller devoted a quarter of his 25-page report to their concerns before finally dismissing them.

"We know now that at the scene of the wreckage of the workers club, people of all walks of life and all rescue services worked wholeheartedly and bravely to try and save survivors and locate bodies," Waller wrote.

"Decisions were taken on good grounds. No life was lost which could have been saved, and no rescuer was seriously injured. All rescue services had their heroes." And they were not alone.

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