Three rescue units, five helicopters and multiple fatalities. The wedding bus lay on its left side with its 35 trapped passengers when emergency services arrived to the carnage late on Sunday night.

Within 45 minutes of the first emergency call, NSW Ambulance commander Luke Wiseman was at the Hunter Valley crash scene.

Nine passengers were already dead. Another died en route to hospital.

“It was a complex operation,” he told Sydney radio radio on Tuesday.

“Unfortunately, as we all know, not everyone could be released (from the bus).”

Police said bus driver Brett Button lost control of the vehicle as it entered a roundabout in fog about 20 minutes after leaving a wedding at Wandin Estate winery in Lovedale.

Emergency services workers smashed the front windscreen and used the airbags to elevate the bus in a bid to free survivors.

Helicopters were unable to land close by, due to the thickening fog.

“It was challenging – (we were at) an isolated location,” Supt Wiseman said.

“You had multiple people on the bus and as we all know, health (services) is really, really pressured.”

Some of the injured were transported to Sydney hospitals by helicopter.

Acting Police Assistant Commissioner David Waddell said 14 wedding guests aged from 20 to 60 remained in hospital with a range of injuries, while 12 have been released.

“Some of our police are visibly distraught,” he told reporters on Tuesday.

“The initial response was quite chaotic for those attending police and other emergency services.”

Supt Wiseman said one of the first arriving on the scene was a young paramedic undergoing training.

“She had just completed her duty,” he said.

“It was within the first 15 minutes of her drive home that she actually came across the incident.”

Premier Chris Minns visited John Hunter Hospital to speak to emergency department staff who dealt with an influx of trauma patients in the middle of the night and paid tribute to the professionalism and dedication of all the emergency workers.

“It would surprise no-one … that those people were on-site working hard on behalf of the state almost immediately,” he told ABC TV.

“They were doing it with dedication and professionalism, but we need to make sure we’re there for them in the coming weeks.

“This is going to be a traumatic few weeks, perhaps even worse than the initial shock of learning of the disaster on Sunday night.”

More charges are expected to be laid against a driver accused of being responsible for one of Australia’s worst bus crashes.

Brett Button is accused of driving dangerously fast in fog through a roundabout moments before his bus tipped over and crashed into a guard rail near Greta in the NSW Hunter Valley on Sunday night.

The 58-year-old sat with his head bowed during a short bail hearing in an overflowing Cessnock Local Court on Tuesday.

While the statements of 10 passengers about Button’s “prolonged behaviour” before the crash made for a strong prosecution case, magistrate Robyn Richardson agreed his family ties and bail conditions could reduce his risk of fleeing the country or interfering with witnesses.

It was clear Button was suffering along with the rest of the community, which was devastated by the crash, and there were concerns for the driver’s wellbeing, she said.

Ms Richardson granted him bail despite strong police opposition.

Button faces 10 counts of dangerous driving occasioning death and a backup charge alleging negligence.

He could expect to be charged over the injuries caused to survivors, including those seriously injured, a prosecutor told the court.

The case was adjourned to August 9.

Button was taken to hospital for mandatory testing but had emerged relatively unscathed from the crash.

The damaged bus has been moved to Newcastle for further examination.

Interviews with bus passengers, including the 26 injured, continue.

Some 14 remain in hospitals across the Hunter Valley and Sydney, including two in intensive care at Newcastle’s John Hunter Hospital.

The group’s injuries range from deep cuts to broken bones and prognoses vary.

Police were still working to contact all families of those killed in the crash, who are spread across regional NSW, Melbourne and Queensland.

Acting Assistant Police Commissioner Tracy Chapman on Monday said emergency responders smashed the front windscreen of the bus in order to pull people from the wreckage.

The crash was a tragic end to the fairytale wedding of Mitchell Gaffney and Madeleine Edsell, both highly involved members of local AFL club the Singleton Roosters.

The Warrandyte Cricket Club in Victoria, where Mr Gaffney previously lived, said a number of its members were involved in the crash.

Greece’s Ministry of Foreign Affairs shared their condilences on Twitter and expressed their solidarity to the Government and people of Australia.

“Profoundly saddened by the tragic loss of life in a bus crash in Hunter region, #Australia. Our heartfelt condolences to the bereaved families & wishes for swift recovery to the injured. At this time of sorrow, #Greece stands in solidarity w/ the people & Gov’t of Australia.”

Profoundly saddened by the tragic loss of life in a bus crash in Hunter region, #Australia. Our heartfelt condolences to the bereaved families & wishes for swift recovery to the injured. At this time of sorrow, #Greece stands in solidarity w/ the people & Gov’t of Australia pic.twitter.com/YSfcbIXays

— Υπουργείο Εξωτερικών (@GreeceMFA) June 12, 2023