Police will today allege in court the 58-year-old driver of the bus which crashed in the Hunter Valley, killing 10 people, was driving "too quick" as he entered a roundabout, rolling the coach.
Acting Assistant Commissioner David Waddell said Brett Andrew Button, from Maitland, was facing a range of "very serious" charges relating to the tragic deaths of guests who had spent that day celebrating a wedding.
"He entered that roundabout driving in a manner that was inconsistent with the conditions," Waddell said.
READ MORE: Victims of Hunter wedding bus crash identified as community mourns
"The speed was too quick for him to negotiate that roundabout, causing the vehicle to fall onto its left side and cause those injuries."
Police had investigated the bus at the scene, leaving many officers "visibly distraught", Waddell said.
There were reports of heavy fog in the area that night.
"The whole conditions will be examined as part of the investigation," Waddell said.
"So, it will be about how the driver drove in relation to the conditions."
Button is facing 11 charges, 10 dangerous driving charges relating to each victim, and one of negligent driving.
He's been refused bail.
Investigators will today conduct a mechanical examination of the bus, after it was removed from the roundabout last night.
The crash scene remains cordoned off and closed.
READ MORE: How the Hunter Valley wedding bus crash emergency response unfolded
Waddell this morning outlined in broad strokes what police allege happened after the bus departed the Wandin Estate Winery, near Greta, around 40km north-west of Newcastle.
About 11:30pm on Sunday night, Button was driving the large white bus in a southerly direction on Wine Country Drive, he said.
The bus was carrying guests following the wedding of newly-married couple Mitchell Gaffney and Maddy Edsell, who grew up in Melbourne before moving to NSW.
There were 37 passengers on board, ranging in age from 20s to 60s, according to police.
As the bus entered a roundabout, to turn west onto the Hunter Expressway, Button allegedly lost control of the bus and it rolled onto its left side, onto a guardrail, Waddell said.
Nine people died at the crash site, and one died later in hospital.
"It was a very chaotic scene," Waddell said.
READ MORE: Heroic stories from tragic wedding bus crash emerge
READ MORE: What we know about the fatal Hunter Valley wedding bus crash
Twenty-five people were rushed to hospital with a range of injuries. There are still 14 people in hospital, two in intensive care.
Waddell described the ICU patients as "critical but stable".
Police have interviewed some of the surviving passengers, he said.
Button was arrested and taken to hospital for blood and urine tests, and he was cleared of serious injury.
He was taken back to Cessnock Police Station where he was charged and held overnight.
Button is scheduled to appear before Cessnock Local Court this morning.
Sign up here to receive our daily newsletters and breaking news alerts, sent straight to your inbox.
