Three people were killed and 23 others were injured just before rush hour on Friday after a double-decker bus crashed at a busy transit station in Ottawa.
Ottawa police chief Charles Bordeleau said the bus driver was arrested at the scene and taken in for questioning, but he declined to provide further details.
The accident happened at 3:50 p.m. local time on Friday when the second floor of the bus struck the roof of the Westboro bus station, which is located in the city's Westboro neighborhood.
Authorities responded to the scene and discovered the vehicle "had run into the bus platform at Westboro station", which resulted in numerous injuries on the bus and platform, according to police.
Investigators worked through the night and identified the three victims and contacted their families, said Const. Amy Gagnon.
"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.
Scott Street and the Transitway were closed between Westboro station and Tunney's Pasture.
Witnesses described passengers being flung from the top of the bus out the front window.
"Road closures remain in place near the scene of the collision and we ask for the public to avoid the area".
OC Transpo has been struggling with a bus driver shortage and chronic service problems as they transition from busses to the new, delayed LRT line.
"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. "I know all those impacted by this tragedy will be surrounded and supported by many", Bordeleau wrote in a tweet published late Friday evening.
One of the deceased was standing on that platform, while the two others were on the bus. Of those transported, 14 were in critical condition and 11 were in serious condition, paramedic chief Myles Cassidy said at a news conference.