The man who died in yesterday's hot ink vat tragedy in Sydney's west has been identified as businessman and father-of-three Craig Tanner.

The 42-year-old from Engadine, in Sydney's south, was killed in an ink vat at DIC Australia’s Auburn factory just before 9am has been remembered as a devoted and loving father of three young boys.

Mr Tanner, who ran Complete Blasting Services, and two of his colleagues, aged 28 and 29, became trapped when a mixing blade suddenly started working while the tank was being cleaned at the factory.

The man who died in yesterday's hot ink vat tragedy in Sydney's west has been identified as businessman and father-of-three Craig Tanner. (Facebook)

One of the two survivors has been discharged from Westmead Hospital and the other remains in hospital in a stable condition, a spokesperson told 9NEWS.

Mr Tanner was a contractor and was inside and cleaning the tank when the blade started moving and cut into his legs.

Tributes have been flowing for Mr Tanner online today.

Mr Tanner with his sons. (Facebook)

Mr Tanner was the owner of Complete Blasting Services. (Facebook)

"You will live in our hearts forever," a woman posted on Facebook.

"You were one in a million with your ever-ready smile, friendship and the love and support you showed to your family and friends.

"No words can express just how much you will be missed."

Another woman wrote: "It is so terrible and so heartbreaking. Such a happy, delightful young man, full of life and love."

The rescue mission took several hours. (AAP)

This morning, authorities have vowed to hold whoever is responsible for the tragic factory death to full account.

There is expected to be a thorough investigation into the horrific incident, especially on how the mixing arm of the large vat accidentally switched on when the men were inside it at the time.

Two of the men were cleaning the machine when the mixing arm started moving, trapping them by their legs.

A third man, who got in to help, also became stuck.

Rescue crews arrived to find the three men inside the vat covered in black ink, rendering it difficult to treat their injuries.

They worked for hours to free the men but could only reach them through a manhole.

Emergency services responded to the industrial accident in Auburn. (AAP)

“It’s totally unacceptable. No worker should go to work and be injured on the job, let alone lose their life,” Minister for Innovation and Better Regulation Matt Kean said.

“We will do whatever is necessary to get to the bottom of what has gone on and hold those who are responsible to account.”

The first man was freed at the scene on Chisholm Road about 10am and was transported to hospital with leg fractures, while the second was extricated by emergency services about 11am.

NSW Police confirmed the third man died just before midday.

“Despite the great efforts by all emergency service personnel on scene, it its tragic that this has occurred at this time of year, so close to Christmas,” Supt Turner said.