Just after 11.30pm, emergency services were called to the roundabout on Wine Country Drive near the Hunter Expressway off ramp at Greta, after reports a coach had rolled.
Initial inquiries indicate 10 people have died.
Another 11 people were taken to hospital, while 18 passengers were uninjured.
The driver of the 57-seat bus, a 58-year-old man, was taken to hospital under police guard for mandatory testing.
It’s believed the bus had been carrying guests who had just attended a wedding at the nearby Wandin Estate winery.
Six helicopters and multiple ambulances were involved in transporting patients, with some going to John Hunter Hospital, others to Mater Hospital in Newcastle, and some even to Sydney.
Helicopters were hampered from landing at the crash site due to fog and had to divert to a nearby housing development.
One wedding guest told Today it had been a “fairytale” wedding, with the attendees keen to continue the revelry before the crash.
“We just got the news that there has been a crash and we all started panicking,” he said.
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“Nobody knows what is going on.”
Cessnock Mayor Jay Suvaal said it was “absolutely horrific” news.
“My thoughts are obviously with the people involved in the accident, but their families and friends as well as the first responders on the scene, because it must have been truly horrible for them as well,” he said.
He said it would send “shockwaves” through the community.
“We are a close-knit community, and there will be massive showings of support I would imagine throughout the day,” he said.
An investigation into the crash is underway.
Drivers are in the area are advised the site of the crash is likely to be closed off for some time, with blocks and diversions in place.
Hunter Valley bus crash: What we know
- A bus carrying guests from a wedding in the NSW Hunter region overturned at about 11.30pm.
- At least ten people have been confirmed dead, and a further 11 have been taken to hospital.
- The driver, a 58-year-old man, has been taken to hospital for mandatory testing.
- Road blocks and diversions are in place and are likely to remain there throughout the day.