For the first time in 40 years, the victims of Australia's worst train disaster have received a formal apology in New South Wales Parliament House.

Key points: Granville was Australia's worst train disaster with 83 people killed

Granville was Australia's worst train disaster with 83 people killed The commuter train from Mount Victoria derailed at Granville in 1977

The commuter train from Mount Victoria derailed at Granville in 1977 40 years on, the NSW Government has apologised for its role in the tragedy

Eighty-three people died and 213 were injured in the crash on January 19, 1977.

Premier Gladys Berejiklian offered a "deep and sincere apology" to the victims and surviving family members of the disaster.

"There are tragic days in history which have a lasting impact on our collective memory," she said.

"We very rarely see them coming but the way we choose to respond to them have a profound and lasting effect on victims that have loved ones and the community more broadly. 18th January 1977 was such a day."

Approximately 50 people linked to the disaster sat in the gallery at NSW Parliament House.

They bowed their heads, wiped back tears, smiled and clapped as the Premier apologised.

Ms Berejiklian formally apologised in NSW Parliament. ( AAP: Joel Carrett )

The Premier thanked all Sydneysiders — emergency service workers, rail staff and volunteers — who helped in the aftermath of the crash.

"They all did their services proud in an extremely difficult situation. I want to take this opportunity, 40 years [on from] that sad and horrific day, to acknowledge and apologise on behalf of the State Government to all those who still suffer today as a consequence of what happened that day.

"Unfortunately the support that many first responders should have received at that time, they did not receive, and we are deeply sorry about that.

"You carry the pain and the scars, but you've also taught us many of the lessons that we have since applied in the last 40 years."

Putting to rest 'survivor guilt'

Nerelle Dean survived the Granville train disaster while she was three months pregnant with her daughter Amy.

Ms Dean attended the apology with her younger daughter Emma Husar, who is the federal MP for the seat of Lindsay, which covers Penrith.

Emma Husar attended with her mother Nerelle Dean (right) who survived the crash. ( ABC News: Philippa McDonald )

"This year was the first time I'd been back. I went the day before the anniversary because I just wanted to do it alone," she said.

Today has been cathartic for Nerelle and her daughters.

"I could put to rest the survivor guilt … for a long time I felt guilty because I survived and there were children that died."

Daughter of disaster acknowledged by Premier

Meredith Knight was just 15 when she lost her father in the disaster when the packed commuter train derailed and the overhead railway bridge collapsed, crushing those in the carriages underneath.

At the time, the NSW Government paid for funerals and gave some assistance, but many received no compensation at all and endured grief and hardship.

"It was sheer deliberate negligence because they knew they had cut back on maintenance and I think the train disaster would not have happened occurred if the proper standards had been followed," Ms Knight said.

Meredith Knight lost her father in the Granville train accident. ( ABC News: Philippa McDonald )

"I believe the Government tried to cover it up afterwards because there would have been massive payouts in compensation because a lot of people had children and a lot of the people that were killed were travelling to work to the city."

In the wake of the disaster, the NSW Government made a massive investment to modernise the state's trains and track, which had been labelled "ramshackle".

Ms Knight and others, including one of the first ambulance officers to attend the tragedy, Barry Gobbe, have been calling for an apology from the NSW Government.

"It's recognition the Government didn't handle it properly," Mr Gobbe said.

"There was no minute's silence back then. I will probably shed a tear for the people who are finally getting recognised in Parliament."

The Premier acknowledged the contribution of both Mr Gobbe and Ms Knight in her address, reflecting they had a role in bringing "this apology to the Parliament today".

Survivors, victims' families and first responders were invited to attend the Premier's address to Parliament. ( ABC News )

Many survivors not attending

The NSW Government has described today's event as "a formal recognition to the victims of the Granville Train Disaster".

Survivors, victims' families and first responders were invited to attend the Premier's address and a morning tea afterwards.

The Granville Train Disaster Association has told the ABC it would make a statement to Ms Berejiklian, thanking her for her "words of compassion" and commending the Government for recognising the "suffering and hardships caused by the mistakes, both deliberate and inadvertent, of their predecessors and endeavours to make restitution".

"However, they will also point out that the grievous decisions and actions of the governments of the 1970s which led to Australia's worst preventable rail disaster, and the resulting injustices perpetrated on those directly impacted, can never be erased," they said in a statement.

"Many relatives and survivors are not attending today because they feel that the apology is 40 years too late. Many find it too painful."

'I think about Granville every day'

Phillip Pitkin travelled from Glenmore Park with his daughter, Virginia, to attend the event.

"To be quite honest I think about Granville every day," he said.

Sorry, this video has expired 'She still had a pulse': Granville survivor reunites with rescuer

"I just made a quick decision and jumped out [of the carriage], everything came straight down and I was hanging upside down for the next three-and-a-half hours."

He counts himself as one of the lucky ones.

Phillip Pitkin survived the Granville train disaster at age 23. ( ABC News: Philippa McDonald )

"I was only trapped from the ankle down and my foot was completely crushed and my third toe disintegrated and my hip was completely pulled out of the socket," he said.

Mr Pitkin married a nurse he met while he was in hospital and went on to have five children.

He said he would today remember the hardship and suffering of others.

"Eighty-three people passed away and I think they should have had an apology straight after the event in 1977," Mr Pitkin said.