“I didn’t see it actually happen, I just heard the noise ... the crash.

“It wouldn’t have been five minutes and the police were here, seven car loads of them, two ambulances and they took a bloke away.”

“One of the guys was screaming, I think it might have been his mate who got hurt.”

Emergency services, including four paramedic units, responded to reports that a pedestrian had been struck by a bus in a car park on Smithfield Road just before 10am.

He suffered critical head injuries and died at the scene.

Paramedics treated another man at the scene for shock, before taking him to Liverpool Hospital.

Officers from the Metropolitan Crash Investigations Unit will conduct a full investigation. The driver has been taken to hospital for mandatory tests.

Transport for NSW has been contacted for comment.

Transit Systems chief executive Clint Feuerherdt said the company was in a "state of shock and grief," over the accident at the routine training session.

"Our sympathies are with the family of the trainer, who was much respected by his colleagues,” he said.

“We are cooperating with officers from the Metropolitan Crash Investigation Unit, who are currently at the scene conducting a full investigation."

Counselling and other support has been available to next of kin, trainees and staff of Transit Systems.

A Fairfield City Council spokesman confirmed that the accident occurred during ongoing training for already licensed bus drivers.

"Council has been advised that the person who was fatally injured was a part of the bus company’s
training program. The matter is currently under police investigation."