The accident just outside a suburban station in the city's west end caused Via Rail to cancel trains on its Ottawa-Toronto route.
Witness Mark Cogan told C424 TV said the rail barrier was down.
"The train is going through," Cogan said. "And I was just looking around, just watching things happen.
"And noticed that in the bus lane, the double-decker bus ... I saw him, and he just kept going.
"I just thought maybe there's a side way around or something, but instantly, he just . he smoked the train.
"He went through the guard rail and just hammered the train, and then it was just mayhem."
More top news
It's a cloudy start for many with some rain around, mainly in the north and west
The hearing will focus on the law that forbids abortion in cases fatal foetal abnormality or where the pregnancy arises through a crime.
Perkins said Weinstein repeatedly sexually harassed her, starting when he asked her to massage him while he was in his underwear.