At least six people have died after a passenger train collided with a double-decker bus in the middle of the morning rush hour in Ottawa, Canada.
The crash happened at 8.48am just outside a train station the city's west end.
Ottawa fire department spokesman Marc Messier told broadcaster CTV there were "multiple fatalities' and 30 others injured.
Five people died at the scene, and one other has since died in hospital.
The Via Rail company operating the affected train on the Ottawa to Toronto line reported no fatalities.
The OC Transpo bus was on its way downtown during the morning rush hour when the accident happened, according to local media reports.
Witness reports say the bus driver appeared to drive straight through a lowered crossing barrier.
The front end of the bus was ripped off in the crash.
Tanner Trepaniere, who was on board the bus, said passengers could see the train coming towards them as the bus approached the crossing.
She said: "People started screaming, 'Stop, stop!' because they could see the train coming down the track."
Another witness, Mark Cogan, told AP that the bus just kept going. According to the BBC, he said: "I saw him [the bus driver], and he just kept going. He went through the guard rail and just hammered the train, and then it was just mayhem."
Bus passenger Gregory Mech, told CBC: "From what I can tell the bus driver did not notice that these train track's signal lights were on and the gates were down. People screamed on the bus shortly before the crash because he was not stopping."
Transportation Safety Board of Canada spokesman Chris Krepski told CBC News Network the investigation could take up to a year.
According to Sky News and the Daily Telegraph, he said: "Obviously we'll let the first responders do their work. Once their work is complete we'll start to take a closer look at the accident scene, document the wreckage, take some photos of the wreckage.
"We'll also take a very close look at the crossing design, what the sight lines were at the crossing, whether or not any kind of warning or protection systems at the crossing were working.
"We'll also examine the data from the locomotive event recorder, similar to a black box on an aircraft, which documents what controls were being used at the time of the crash."
Prime Minister Stephen Harper wrote a message on Twitter expressing his condolences. He said: "Deeply saddened to hear about the bus-train collision in Ottawa this morning. Our thoughts and prayers are with the families of those involved."
Ottawa Mayor Jim Watson said the crash was the worst in the city's history.
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