The crime scene seems to go on forever, a taped off stretch of street scattered with bodies under orange sheets, urban debris and a pair of abandoned shoes.
Toronto police have arrived, and a suspect is under lock and key, but no one yet knows why the driver of a white rental van spread death and destruction under the warm spring sunshine.
"I heard screaming, yelling. I turned back and saw this truck going that way. He was going in and out, back and forth, zigzagging. He just kept on going," said 42-year-old Rocco Cignielli.
There was nothing the customer service worker could do. Emergency services were on the scene quickly, but in some cases their efforts were in vain.
At least 10 people have died in the attack officials called "deliberate" but not linked to national security concerns.
"I saw there were people lying on the ground. I saw they were doing heart compression, and I saw two people dying right here in front of me," Cignielli told AFP, pointing at the bodies.
It was shortly after 1:00 pm (1700 GMT) on a working Monday when the speeding van hit this commercial thoroughfare in a district of high-rise residences in the north of Canada's biggest city.
A pale but cheery sun shone after a long and grim final winter stretch even by the region's standards. Many local people were out and about.
Nana Agyeman Badu, a 56-year-old taxi driver, saw the van heading south toward central Toronto, where ministers from the G7 world powers were holding a security conference.
Then the van swerved onto the sidewalk.
"I thought maybe he was making a delivery. But I was thinking, 'Why would he drive in the pedestrian walkway like that?' Very fast. Then I saw he had already run over some people," the witness said.
"A lady was walking towards the car close to a bus shelter. The truck pinged the lady through the bus shelter and she fell back and all the broken glass fell onto her," he added.
"I stopped and ran out to help her. The truck continued going and going and going."
The truck smashed a yellow fire hydrant, a few newspaper dispensers and there, a bit further, lie a pair of sneakers.
"They belong to a victim," a police officer said.
Some in a crowd that gathered by the police tape as dozens of rescue vehicles were deployed were dumbfounded. "It is a dangerous crossroads," one woman suggested.
"Oh, it was no accident," declared another passerby.