The 57-year-old was riding with five others in the NSW Hunter Valley region yesterday when the bus rolled seven times down an embankment at Mount View about 10.30am.
He was trapped inside the crumpled vehicle for 45 minutes as paramedics worked to free him.
Barrett, a father of four, was mere hours away from marrying his fiancee Michelle Murphy when the bus crashed.
He was taken to hospital in a critical condition with injured limbs along with a 60-year-old man who suffered head injuries.
They were treated by a specialist team on the ground before being airlifted to John Hunter Hospital in Newcastle.
Four other members of his wedding party suffered minor injuries and were transported by ambulance.
Barrett and his family are regulars at Bistro Molines where the wedding reception was scheduled to take place.
Barrett was recently diagnosed with motor neurone disease (MND) and his family had been raising money in support of Professor Dominic Rowe, who runs clinical trials for the disease at Macquarie University.
“This cause is deeply personal to us. As many of you would know John was recently diagnosed with motor neurone disease (MND),” a fundraiser for Barrett reads.
“While we are adjusting to this unfamiliar journey together John was quite clear that he wanted to do what he could to raise funds in support of Professor Dominic Rowe and his team at Macquarie University.”
NSW Taxi Council chief executive Nick Abrahim said the manager of the taxi business spoke at the scene with the driver, who had some injuries.
“He did seem OK,” Abrahim told 9news.com.au.
“We’re just grateful that everybody was able to get out.”
Police said the driver will undergo mandatory blood and alcohol testing.
Officers are now combing the area and looking at footage to determine how the crash took place.
Police yesterday described the crash as tragic.
”It’s a tragic situation, they hadn’t actually got to the wedding yet, so they still have a wedding in front of them,” NSW Police Superintendent Steve Laksa said.
“We’re very fortunate that the injuries weren’t fatal. It definitely could’ve been worse.”
The incident follows the wedding bus crash in the Hunter Valley in June 2023 which killed 10 people and injured 25.
