'It's chaos': Fifteen passengers taken to hospital after train crashes into wall at Richmond Station

More than a dozen people have been taken to hospital after a suburban Sydney train hit a railway buffer "at speed" at Richmond Station in the city's northwest.

Witnesses say passengers and crew were "sent flying" when the train crashed at the end of the line just before 10am on Monday.

A total of 16 people - including the driver and another staff member - were treated at the scene, NSW Ambulance said.

Fifteen were taken to various hospitals in the area for treatment, including a 21-year-old man with a suspected broken leg.

A 70-year-old woman has been taken to Westmead Hospital for treatment and two others have been transported to Nepean.

The remaining patients suffered less serious injuries - largely back and neck pain and cuts and bruising, NSW Ambulance's Paul Turner said in a statement.

Sydney Trains boss Howard Collins said it was too early to speculate on the cause but, from what he had seen, the buffer stop worked "effectively" and stopped the train from derailing.

'It's all chaos here'

Witnesses have described a scene of chaos, with the train apparently hitting the buffer at the end of the line "at speed".

North Richmond resident Broady Graham was arriving at the station with his friend just after the crash happened.

“We didn’t know what was going on,” he told Yahoo7 News.

“Everyone on the station was just really shocked, police told us to get off the platform because we couldn’t be blocking the area.”

“The train looked like it was lifted up onto the barrier, it was pretty chaotic at first and then more emergency services came to the scene.

One caller to Sydney's 2GB radio who saw the crash said there was an "almighty bang".

He said the train came in at speed and hit the buffer and rebounded.

"There was a huge amount of dust," he said.

"It's all chaos here," another caller, Steve, told the station.

Sydney Trains boss Howard Collins was seen leaving union negotiations to deal with the incident at Richmond Station.

NSW train strike meeting suspended

Unions were due to meet with Sydney Trains at 11am on Monday to nut out negotiations over the looming 24-hour NSW train strike next week.

"Sydney Trains management has postponed the meeting to deal with the unfolding news of the incident," a Rail Tram and Bus Union spokeswoman told AAP.

More than 9000 Sydney train workers are set to strike on Monday, January 29, as they push for a six per cent pay rise and improved conditions.

The government has been holding firm on a 2.5 per cent wage increase.

"We will wait to hear from Sydney Trains to find out when negotiations will resume," the union spokeswoman said.

Transport Minister Andrew Constance, who last week described the strike as a "silly stunt," met with union officials on Friday in an attempt to come to an agreement.

RTBU NSW secretary Alex Claassens said on Friday he believed Mr Constance was committed to "trying to resolve this mess".

The main issues that remain to be resolved include rostering, job security and working conditions.