The Warrigal Care minibus was carrying 11 people when it collided with a the front end of a fuel tanker and flipped across the northbound lanes of the M1 shortly before midday, Wednesday. 

Paramedics who were first to respond called on NSW Ambulance to “keep all resources coming” after they were met by a large number of the injured.

Eight seniors, two staffers and a volunteer driver were on the bus when it came unstuck.

Superintendant Zoran Dzevlan, of Lake Illawarra Command, said one of the bus passengers did not survive. 

“They [the other passengers] are all in shock,” he said.  

“Both drivers have been conveyed to hospital for mandatory blood and urine testing.” 

The Mercury understands at least one person from a separate vehicle required medical attention. 

The injured bus passengers were not residents of a Warrigal Care facility but were taking part in its social outreach program, called Club Connect. 

The company’s acting CEO, Leanne Taylor, said the group was bound for a barbecue at a park in Dapto. 

"As soon as we became aware there'd been an accident we immediately contacted the families of the people who'd been involved to let them know they were on the bus, to let them know there had been an incident,” Ms Taylor said. 

“As information has become available we've been maintaining that contact with them, we've got staff in two hospitals where those who were injured are being cared for.

“We are extremely shocked and saddened and our immediate response was to support everyone involved.”

Among the injured is an 80-year-old woman who was transported by road ambulance to Illawarra Regional Airport, then airlifted to St George Hospital, where she remains in a critical condition. 

Six people were transported to Wollongong hospital including an 86-year-old woman who remains in a serious but stable condition. 

Three women (aged 88, 77 and 78) and a man aged 88 remain at the hospital in a stable condition; a 53-year-old woman was discharged later Wednesday afternoon. 

Two women aged 37 and 85 and two men aged 64 and 63 were transported to Shellharbour Hospital, all in a stable condition. 

Mark Parry, managing director of Rob Finemore Transport, said the B-double tanker involved in the collision was carrying liquid petroleum product from Nowra to Sydney. 

Mr Parry said the company’s driver was physically well. 

“We’ve spoken to our driver and he’s unharmed.”

“Senior managers are going to the site now and we’re helping authorities with the accident investigation.

“We’re aware from media reports that there has been a fatality. Obviously our thoughts go out to the families involved.”

Northbound lanes of the M1 were closed for four hours as emergency services cleared the site and a police investigation got underway.

Officers from the Crash Investigation Unit are handling the police investigation and are calling on any witnesses to make contact.