Police and a first responders work at the scene where a double-decker city bus struck a transit shelter in Ottawa, on Friday, Jan. 11, 2019.
Six people were killed and 34 more were injured.
The collision of the OC Transpo double-decker bus happened on the westbound Transitway just before 4 p.m. local time (21:00 GMT).
Four hours after the crash, Ottawa Hospital said that seven patients were in a critical condition and nine in a stable condition.
Bilal Gill, a passenger on the upper deck, told broadcaster CBC News that people at the front were pinned under their seats. Road closures remain in place near the scene of the collision and police are asking the public to avoid the area.
"We're taking every necessary step to establish all of the facts and will co-operate fully with any investigation", said John Manconi, the general manager of Ottawa's transit service, OC Transpo.
The bus had a capacity of 90 people, both sitting and standing.
"Please keep victims, witnesses, families and our awesome first responders in your thoughts". Bordeleau said new information has surfaced to challenge that account, but did not provide further details.
Those who have pictures or video of the crash are being asked to get in touch with police, while passengers on the bus missing property are also asked to reach out.
"I was shocked to hear of this horrific incident", Ottawa Mayor Jim Watson said.
"I want to send my deepest condolences to the families of victims and everyone affected by today's tragic bus crash", Prime Minister Justin Trudeau tweeted. In that case, an investigation found that the cause was a combination of excessive speed, a hard curve before the tracks and driver distraction from video monitors showing the upper deck.