'Miracle More Didn't Die': Train May Have Been Speeding Before It Derailed, Killing Two

A train driver and another worker have been killed in a terrifying train derailment north of Melbourne.

Police said it's a miracle more people weren't killed when the Sydney to Melbourne XPT -- which had 153 passengers on board -- came off tracks near Wallan Station, 45km north of Melbourne on Thursday evening.

The 54-year-old male driver from the ACT and his 49-year-old male co-driver were killed, police confirmed.

Twelve people were treated before being taken to hospital. Among those was a 60-year-old man who was taken to the Royal Melbourne Hospital in a stable condition after sustaining an upper-body injury.

The engine and the first carriage off the train tipped onto their sides while five others were believed to be leaning off the wrecked tracks.

"I imagine as a first responder who turned up it would have been looking like a horrific scene," Acting Inspector Peter Fusinato said.

"I'm very surprised there weren't more serious injuries. Quite a miracle really."

There are reports one man was injured while trying to save the driver, and Fusinato said he expected further stories of bravery to emerge.

Investigators will examine whether the train that derailed north of Melbourne, killing the driver and pilot, was speeding to make up time.

Police are urging people who left the scene without speaking to emergency services, or who bought tickets but didn't board the train, to come forward.

Passengers boarded buses to Melbourne following the crash, while others were picked up by family.

A spokesperson for the CFA said three helicopters had also attended the scene to help transfer the injured. While a local McDonald's and BP were being used as a temporary triage centre.

10 News First spoke to one passenger who was on board the train when it derailed.

Alisha Van Es said she felt lucky to be alive.

A Sydney couple who were on their way to visit their son in Melbourne said the crash and its aftermath were terrifying. They've cancelled their return trip.

The train was running two hours late when it derailed. Image: Scott Rickard.

"You just hang on for grim death. You're being thrown around, the thing's going along tilting over and all you can look out the window and just see dirt and debris and stuff flying up past the windows and the track itself is just twisted and bent," the man said.

"It probably went about 150 metres before it stopped, there were carriages going sideways - pretty horrifying."

The woman said her thoughts were with those who had died.

"We're very sad about that. Two people who went off to work this morning and never went home," she said.

It is understood the train had already experienced a lengthy delay due to problems with the signals on the line.

The train was supposed to depart Sydney's Central Station about 7.40am and had been due to arrive at Southern Cross Station in Melbourne at 6.30pm.

The track buckled and both carriages shifted at least 10 metres from their normal trajectory, reports suggest.

A crime scene has been established and a joint investigation is underway between the National Rail Safety Regulator, Australian Transport Safety Bureau and WorkSafe.

This could take some time given it could be days before the train can be removed from the tracks.

With AAP.