The catastrophic repercussions from the Hunter wedding bus crash continue one year on.

The still untold horror and apparent chaos amid the extraordinary grief and heartache that enveloped an otherwise nondescript Hunter Valley roundabout quicker than the thick fog that was rolling in.

Experience told Paul O’Keefe to meld into the background and take in the scene.

The chaplain had seen a lot in his eight years with the NSW Disaster Recovery Chaplaincy.

But nothing like this - after a coach carrying 35 wedding guests rolled at Greta and, in doing so, also into the collective Australian psyche forever.

And with it a name etched in the nation’s road tragedies forever - Brett Button.

The 59-year-old coach driver was affected by opiate painkillers and making weird boasts to passengers as he sped into the roundabout at 56kmh, despite the Linq Buslines bus having a “tipping threshold” of just 31kmh.

He would later plead guilty to 10 counts of dangerous driving occasioning the death after prosecutors controversially dropped manslaughter charges.

That was still months away as O’Keefe’s instincts told him on that cold Monday morning that he also needed to soak in the grief and despair as hundreds congregated near the crash site.

“No one can appreciate the grief of losing so many young people and of course, husbands, wives, brothers, sisters, sons, daughters, all that,” he recalls.

The chaplain met with first responders, relatives, friends and onlookers, telling The Daily Telegraph his experience in multiple disasters helped him navigate the grief in the community.

“So we give them that space. That said, there are people that just came straight up to me and basically collapsed in my arms,” he said.

“I had young, young children, I had teenagers, who knew the various people, who were absolutely broken. Beyond anything I have seen in my eight years of disaster chaplaincy.

“I haven’t seen grief and despair as like what I saw in those early days.”

Still at the scene on that first morning were the bodies of Rebecca Mullen (26), Zachary Bray (29), Andrew Scott (35) and his wife Lynan Scott (33), Tori Cowburn (29), Angus Craig (28), Nadene McBride (52), her daughter Kyah McBride (22) and Kyah’s partner Kane Symons (21).

Darcy Bulman (30) had been rushed to hospital but would succumb to her injuries.

A further nine people suffered horrific injuries - many life threatening themselves - and a further 16 needed treatment.

Each of them had expected to get back to Singleton safely after a wonderful celebration at Wandin Valley Estate.

Instead, survivors and onlookers clambered through the upturned bus just before midnight looking for survivors amid unquestionably horrific scenes, some of which are too graphic to share.

Button had walked from the wreck, rang a boss to say he had “f--ked up” and was taken to hospital for some treatment to some minor cuts.

But it was mandatory blood tests Button took which would again test the mettle of victims families and survivors, when it was revealed the troubled bus driver was addicted to opiate painkillers and was affected when he drove too fast into that roundabout following a day of odd behaviour and weird boasts.

The grief, that immeasurable heartache, is still too raw for many 12 months on.

The families of those lost are still not in a position where they wish to speak publicly about that day - and the days, weeks and months after.

Many first responders have also had their lives changed forever. Some have gone off on sick leave and have never returned.

Amid the crowd was Matt and Leanne Mullen, whose continued attendance at court proceedings to represent their lost daughter Bec has also made them the defacto face of the grief.

They had never wanted to be in the spotlight - and they still don’t wish to speak on the anniversary because they respect other families’ decisions to remain silent and are aware it may appear they are placing their daughter Bec higher than the other nine who lost their lives.

But Leanne’s open letter to parliament, read by Upper Hunter MP Dave Layzell after the manslaughter charges against Button were withdrawn, gives a heartbreaking insight of the scene.

“I wonder if anyone can imagine what it is like to live with the fact that you stood 20 metres away from your daughter’s dead body, being denied access to your baby girl,” she wrote.

“What it is like to repeatedly try and hold your husband and son back from their desperate attempts to get to her.”

And then later: “To not be able to kiss her forehead, hold her hand, tell her we were there for her, that she was not alone and say all you needed to say about how much she was loved, how proud we were of the person she had become, how we promise we will carry her memory with us for as long as we live.

“Being denied these moments have tormented me. In fact, as I have slowly gained more knowledge, the first 48 hours after the incident haunt me.”

Mr Layzell recalls realising the horror of what was unfolding on that Monday morning of the long weekend after his phone began “pinging” and getting a call from neighbouring MP Clayton Barr that many of those affected came from Singleton.

He immediately knew how far the ripples would flow.

“Dealing with trauma like this is a challenge, to happen to so many families in one go has been an enormous challenge for the community,” he says.

“The period during and straight after was a very traumatic time for a large number of people, as people realised their connections.”

He later adds: “It’s hard to digest all of that at the time.

“Very unsure how you can help those affected at the time, but we had to come in and help the community.

“It was a whole community affected so we set up response centres as a way of supporting the community, social workers, volunteers to help everyone through the event.

“Each family, each person has their own journey to go through.

“We all recognise that journey, people’s level of grief, how much we’ve got to help people but we’re really there to try and mend a broken heart.

“But how do you mend a broken heart, only just be there for them.”

While Cessnock state Labor MP Clayton Barr says it remains hard to believe that a year has passed and that the grief remained raw.

He says a lot of the time has been spent “trying to tread a little bit more carefully”.

“A lot of people around the community that didn’t directly know anyone that was part of that tragedy but they certainly felt the vicarious trauma that has weighed heavily on people,” he says.

“At the moment I think we’re struggling to contemplate that it has already been 12 months.

“There’s enormous empathy and compassion because getting on a bus and going to a wedding is something that almost everyone around here has done.

“People totally understand that the spirit and mood of that night would have been like, the celebration and the sudden tragedy and how difficult that would have been to come to terms with.”

It is a thought that remains with many, including Cessnock Mayor Jay Suvaal, who was away for the long weekend with the family when he heard of the crash.

“So many people have done similar things, gone to a wedding, gone on a bus trip in the Hunter Valley and I think it brought it all home to them about ‘that could have been me’ so that has had a really significant impact on quite a lot of people,” Cr Suvaal said.

He recalls thinking in the immediate aftermath a sense of needing to take some pressure off those most affected.

The crash had made international headlines and there was a hunger for information.

“I wanted to shoulder as much of that burden off the families and victims as I could and make sure they had time to deal with what was going on in their own private space,” Cr Suvaal says.

“Tried to pick up the media airtime to give the families and victims the space they needed to process what was going on.

And he also adds: “It’s a complete shock, it’s not something you expect. You don’t expect an accident of this scale, especially something that has impacted so many lives.

“Makes you reassess your own life and impacts on you and your family. I was unsure what was really going on.”

Dave Layzell still ponders what is next for the survivors and the families left behind, adding the need to read out Leanne Mullen’s letter to parliament was significant.

“How do you fix those broken hearts?” he asks.

“As a society, we all want to help but it’s just so hard, [we] just don’t know what to do.

“Nothing will be the same for them ever again.

“Like looking at the sharp point of an arrow, this is one point but behind it is a trail of destruction and emotions and broken hearts that is throughout the community, throughout the state.

Linq Buslines has also issued a statement on the one-year anniversary.

“On this sombre anniversary, our thoughts and prayers are with the families and friends of those affected,” a spokesperson said.

“We once again extend our deepest, heartfelt condolences to everyone impacted by this tragedy. The Hunter Valley community remains in our thoughts as we jointly mourn this loss.”

Meanwhile, NSW Premier Chris Minns also paid tribute to the 10 lives lost.

“The impact of that night was felt nationwide,” Mr Minns said. “Communities were left heartbroken in Victoria, Queensland, and Tasmania, and in the tight-knit NSW towns of the region – like Branxton, Cessnock, and Singleton.

“Their grief continues to this day.”

The Premier said the first anniversary would be a “painful step” for survivors.

“For the families and friends of those killed and injured, this date will stir many emotions,” he said. “On this day, I want to express the love and support of the wider community – to all those who are suffering.”

Mr Minns also paid tribute to first responders of the crash.

“In the face of life’s cruelty, we take comfort in their kindness and bravery,” he said. “The people of NSW remain with you in your grief and will support you on this anniversary and in the painful years ahead.”

Video: Lachlan Clear

Interactive graphic design: Darren Gover, Steven Grice and Fay Gould