It happened in the eastbound lanes of Highway 403 near Waterdown Road.
Ontario Provincial Police Kerry Schmidt said the crash investigation remains “ongoing.”
All eastbound lanes on Highway 403 are blocked at Waterdown Road.
“We are working to remove these vehicles, but at this time there will be long delays in this area on both sides of the freeway as a result of the distraction and closure,” Schmidt warned.

	Collision with a school bus and a trailer carrying another bus.  27 passengers/children on the school bus.  There are no reports of serious injuries.  All lanes blocked on #Hwy403 eb Waterdown Rd.  #BurlingtonOPP is investigating.  pic.twitter.com/xoyjye0eip
— OPP Safety Division (@OPP_HSD) July 21, 2022