Const. Amy Gagnon says officers worked through the night and identified the three victims and contacted their families.
The driver of the bus was arrested at the scene, Chief Charles Bordeleau of the Ottawa police told an evening news conference at city hall.
Three people were killed and almost two dozen injured in a collision involving an OC Transpo double-decker bus at Westboro station Friday afternoon.
An investigation was opened to determine the cause of the crash, police said, adding that the bus driver was detained "and will be interviewed".
"The upper deck on the bus was compromised and several people were trapped on the upper level for a period of time", the news release said.
The crash took place west of downtown at 3:50 p.m., at the beginning of rush hour, just as dusk was beginning to settle on the coldest day of the winter so far in the capital. Pictures posted to social media show a large presence of first responders at the busy transit station, and substantial damage to the front end of the bus.
OC Transpo has issued notices saying detours are in effect for the Dominion and Westboro transit stations.
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The anti-drone equipment can detect and jam communications between a drone and its operator and was deployed on a roof at Gatwick. Police could also fine drone users failing to comply with authorities or present registration to operate a drone up to £100.
People are being asked to avoid the area as crews help those who have been injured.
She said Ottawa police's collision investigation unit remains on the scene as it continues its examination of the collision.
He went outside and came across a "chaotic" scene, with at least 30 emergency vehicles, including seven or eight fire trucks, and lots of police and bystanders, he said.
"Our (city) community has been rocked today".
The most serious injuries occurred on the top right side of the bus, following its collision with the platform at around 4:00pm Friday.
Three people died; two were believed to have been on the bus, and one person was waiting on the platform.
"Please keep victims, witnesses, families and our unbelievable first responders in your thoughts".