An Ottawa city bus slammed into a Via Rail train at a level crossing during Wednesday’s morning commute, leaving six people dead and dozens injured.

Five people who were on the double-decker bus were pronounced dead at the scene and another person later died in hospital. Thirty-four people were taken to Ottawa-area hospitals.

So far, police have only identified the deceased OC Transpo bus driver, 45-year-old David Woodard. Colleagues said he was married and had a good driving record.

Those who survived the crash said some passengers yelled at the bus driver to slow down seconds before the impact, but it was too late. Witnesses said lights were flashing and the gate was down at the railway crossing when the crash occurred at 8:48 a.m. ET near the intersection of Woodroffe Avenue and Fallowfield Road.

The impact derailed the Via locomotive and one passenger car, but no injuries were reported aboard Train 51, which departed from Montreal en route to Toronto.

The front of the OC Transpo bus was sheared off in the collision. Shell-shocked passengers reported seeing bodies on the ground and first responders crowding around the injured.

"I've seen a few people dead, someone ripped in half," said a tearful Rebecca Guilbeault, who was on the bus with her one-year-old son.

Guilbeault said she was texting her friend when other passengers began yelling at the bus driver to stop.

"As I looked up, the bus was coming into contact with the gate," she told CTV News.

"I don't know what happened," she said. "I don't know if the bus driver like blacked out, I don't know what happened, but he didn't slow down and it just impacted with the train."

Guilbeault said she immediately ran off the bus with her son. It was not known how many people were on board at the time of the crash, but the double-decker bus can carry an about 90 passengers.

"We had bodies and debris pretty much everywhere at the impact site," Ottawa Fire Service's Marc Messier told CTV News Channel.

Ottawa Mayor Jim Watson called it the worst bus accident in the city’s history.

“In literally a moment, we lost six residents of our city,” he told reporters.

At a 4 p.m. media briefing, Ottawa Police Chief Charles Bordeleau said three people who died in the crash have been positively identified. Authorities are now in the process of notifying their families.

The Transportation Safety Board of Canada will lead the investigation, with the help of Ottawa police and the coroner's office.

TSB lead investigator Glen Pilon said the agency's priority is to find the event recorder that was on the bus and the train's black box to determine the circumstances surrounding the collision.

The TSB will also will be checking the warning systems and the gate at the railway crossing to make sure they were working correctly at the time of the accident. Eleven TSB staff members were at the crash site Wednesday.

Pilon couldn't say what speed either vehicle was travelling at the time of the crash, or whether the drivers attempted to break.

He did say, however, that Via crossings are a concern for the TSB since they involve passengers, rather than goods.

"They're just on our watch list," Pilon explained. "Because of the chance for the loss of life, it's one of those things we want to make sure doesn't happen again."

The full TSB investigation could take months to complete, said chief operating officer Jean Laporte.

Local officials said there have been no accidents at the intersection where the crash occurred since 2002 – the year the city started keeping traffic records for that area.

Asked if the crossing where the collision occurred was safe, a city official said all train crossings in Ottawa are considered safe.

OC Transpo general manager John Manconi said officials are still trying to learn the details surrounding the crash.

“We’ll be working closely with all agencies as they determine circumstances what led to this collision,” he said.

Several passengers who take the bus regularly said the driver appeared to be new to the route.

Deaths, injuries ‘overwhelming’

Following the crash, 34 victims were transported to local hospitals. Some came to the hospital on their own, with minor injuries.

A number of people were treated and released, but it was not clear late Wednesday how many still remained in hospitals.

Those with the most serious injuries were rushed to Ottawa Civic Hospital, the regional trauma centre, and Queensway Carleton Hospital.

Dr. Andrew Falconer, Queensway Carleton Hospital Chief of Staff, said most of the crash victims have suffered leg injuries.

"It's definitely one of the worst events we've seen in this city or at this hospital," Falconer told reporters at the scene. "It's overwhelming to imagine the suffering that's going on."

Watson said city flags will fly at half-mast to honour the victims of the crash. A condolence book is also available at city hall.

"Our focus as a city today is to care for those families who have lost a loved one as well to ensure we provide the best possible care for those who have been injured and affected by this accident," Watson said Wednesday.

A vigil for the victims was held on the train tracks near the crash scene Wednesday evening. Dozens of people took part in a group prayer and some sang “Amazing Grace” while holding lit candles.

Some OC Transpo bus drivers attended the vigil in full uniform.

Prime Minister Stephen Harper and Ontario Premier Kathleen Wynne have also offered their condolences to the victims and their families in official statements and on social media.

All Via train service on the Ottawa-Toronto route was cancelled following the collision, and passengers were being transported by bus.

With reports from CTV’s Richard Madan, Omar Sachedina, Daniele Hamamdjian and Katie Simpson