Toronto police said officers were called to Keele Street and Sheppard Avenue West at around 12:25 a.m. for reports of a collision.
A red 2004 Peterbilt transport truck was heading north on Keele and was making a right turn onto Sheppard Avenue West when it struck a pedestrian, officers said.
The pedestrian suffered life-threatening injuries.
The victim was crossing from the southeast corner to the northeast corner and was using the crosswalk, police said.
However, the “exact location of initial contact is still being investigated,” a police spokesperson said.
“It is believed the operator of the truck was unaware of the collision, when they were stopped by responding police officers,” the spokesperson added.
“That operator returned to the intersection and cooperated with the investigating officers.”
The Toronto police Traffic Services unit is continuing to investigate.
Any witnesses or anyone with video footage was asked to contact police.