News says different.
RCMP say multiple factors under consideration in Broncos' team bus crash | CBC News
The driver and sole occupant of a semi-trailer was heading west on Highway 335, while the Humboldt Broncos team bus carrying 29 people was northbound on Highway 35.
Looks like the truck driver may have blown the stop sign, and the bus hit the trailer.
The first news report I heard called it a head on.
But as the article states, it's still under investigation.