The boy was walking to school at 8:40 a.m. with other students on Friday when he was struck by a bus turning right from Sir Winston Churchill Avenue onto Woodlands Road.
There are no lights at the intersection, which is marked by a crosswalk.
Keohane called the boy's death an "absolutely tragic loss" that will have a profound effect on the school, he said.
The bus was carrying students from the public school district at the time.
A critical response team is also at the school to support students, Keohane said.
Alberta Education Minister Jeff Johnson offered his condolences to the boy's family.
"The loss of a young life is tragic and, as a father, my heart breaks for the child's parents," Johnson said in a news release. "My prayers are with the family during this difficult time."