Adelaide's Indian community is mourning the loss of five members of the same family who were killed in a car accident while holidaying in India.

Restaurant owners Rupendra and Anamika Datta were on their way to the Taj Mahal with their family when the accident occurred on Sunday afternoon.

It is believed a burst tyre sent the car into a safety barrier, before the SUV flipped on its roof and landed in the path of oncoming traffic.

Ms Datta, 45, and daughters Nikita and Pipasa, aged 8 and 12, and her sister Sonali died at the scene.

The Dattas' 17-year-old son, Digvijoy, died in hospital a short time later.

He was a student at Adelaide High School.

Mr Datta, 48, and his father-in-law are being treated in hospital after surviving the crash.

Mr Datta, originally from New Delhi, runs the Urban India restaurant on Henley Beach Road in Adelaide.

Urban India has opened its doors to the public today, but chef Manpreet Singh said he was still in shock.

"The family was very nice," he said.

"It's nothing like business, we all work as a family here and they were really very good people.

"We're just doing our responsibility, opening the restaurant, and we want everybody to pray for him now, for his good health."

Close family friend Raja Chaudhuri said Mr Datta, called Rupen by his friends, had been left paralysed from the "waist down" by a spinal injury.

He said he had spoken to a witness who allegedly saw the SUV travelling at excessive speed.

"I saw it on Facebook. Somebody posted that there had been a terrible accident in Delhi so I rang the person," Mr Chaudhuri said.

Flowers were laid outside the Datta family's Urban India restaurant on Henley Beach Road. ( ABC News: Candice Marcus )

"The report is that it was over-speeding, about 140 kilometres per hour. That's what the eye witness said.

"It's an expressway but they shouldn't be going that [fast] and one of the tyres, the back tyre, actually burst. They lost control. The car hit the divider and then it toppled over the divider going into the other lane."

Mr Chaudhuri said his friend would never let anyone go hungry and would feed people who could not afford a meal for free.

He said the Indian cricket team would frequent the Urban India restaurant when in Adelaide.

"The immediate concern at this moment is the consular assistance to Rupen because when he's stabilised, depending on what he wants to do, we can fly him back to Adelaide but then I don't know how he'll piece together his life," he said.

"He's broken, completely broken, like a piece of glass."

Friend Robbie Benipal said the family was very kind and often provided work for new Indian migrants at their restaurant.

"It was like a shock for me, made me cry from inside actually," he said.

"It shouldn't happen with a family who really help others."

The Department of Foreign Affairs said it was providing consular assistance to relatives.

Family were due back in Adelaide

Close family friend, Anand Bhatia, said he was still in shock over the news and that the family had been due to return to Adelaide this weekend.

Rupendra and the late Anamika Datta have been praised for their kindness and generosity by friends. ( Supplied )

"My whole family is in shock," he said.

"I still can't believe it happened to them.

"They are a very nice family; they were a very loving family."

Mr Bhatia said he had spoken to the hospital where Mr Datta was first taken, but he has since been transferred to Fortis Hospital in Delhi.

Mr Bhatia believed Mr Datta had suffered critical spinal injuries.

He believed a third person, the driver of the SUV, was also taken to hospital with injuries.

ABC/AAP