Ottawa's public-transit authority has opened an investigation and apologized after one of its bus drivers threatened and swore at a passenger, a young man who describes himself as being autistic.
Part of the profanity-laced incident was caught on video by another bus rider and posted on YouTube, triggering an uproar in the capital.
The video shows the driver screaming at a man who appears to be in his 20s until the passenger meekly says "sorry" as he runs to the door and disembarks.
"The incident appears genuine. The investigation will be given the utmost attention, given the seriousness of the case," OC Transpo General Manager Alain Mercier said in a statement which apologized to the passengers on the bus.
The passenger who was berated has been identified as Matthew Taronno, 20, a resident of the western suburb of Kanata who studies script writing at Algonquin College.
Mr. Taronno describes himself as being "mildly autistic" and told the CBC that he was in the bus reciting out loud from a script, which he said might have been "inappropriate."
"I know what I did may have offended him and I regret my action and I understand what I did was wrong even though I was saying that for my screenplay and it still may have come off as offensive and I regret that," Mr. Taronno told the CBC.
"But … he [the bus driver]needs to have a consequence for his action for him to understand what he did was wrong," he added.
The person who witnessed the incident filmed the encounter with his mobile phone while riding on the bus from downtown Ottawa to Kanata.
In the video, which appears to have been filmed at night time, the bus is empty except for the driver, the witness and Mr. Taronno.
In a description of the video that he posted on YouTube Thursday, the witness said Mr. Taronno appeared to be mentally ill and was talking loudly.
"The male walked to the front of the bus and started talking to the bus driver. This quickly enraged the bus driver and he started to yell at the mentally ill young man," the witness wrote.
The witness wrote that the driver chewed out Mr. Taronno even though the young passenger tried to apologize.
On the video, the driver can be heard as he screams: "Shut the f--k up. Shut your ignorant cake hole. Don't say another f--king word."
He also threatens violence as the bus nears a stop.
"If you don't shut your f--king face, I'm going to stick my fist in it. Shut up. Not a f--king word. Not a sound. When I open that f--king door, you get out, you don't say a f--king word or I'm going to kick your f--king ass."
Ottawa Mayor Jim Watson said on his Twitter account that he was troubled by the video.
"Like anyone I am very disturbed by what I have seen and heard and want to see a thorough investigation conducted," Mr. Watson wrote Sunday night.
Nikki Eaton, a public-affairs officer for OC Transpo, said potential disciplinary measures may not be disclosed unless the driver is dismissed.
Union officials were quoted in Ottawa media saying that they would co-operate with the probe but that the video may not have shown the full context of the incident.
Transit Union local 279 president Garry Queale also said that a municipal bylaw doesn't allow riders to take pictures in a bus.