Five people — including three children — were injured Friday morning after a school bus and a heavy duty flatbed truck collided in Spruce Grove.
Two of the victims were school-age boys who were taken to hospital in critical, life-threatening condition, Alberta Health Services said.
The collision happened at about 8:15 a.m. at the intersection of Diamond Avenue and Golden Spike Road.
A woman in her 60s was taken to hospital in serious but stable condition, AHS said.
A man in his 40s was taken to hospital in serious but stable condition.
One school-age girl in stable condition was treated at the scene but was not taken to hospital by EMS.
RCMP said the children were between the ages of eight and 13.
In a news release, Parkland School Division said the bus was on its regular route when it was hit by the truck.
"Right now our focus is on our students and their families in the aftermath of such a traumatic event," superintendent Shauna Boyce said in a statement.
"We are grateful for the first responders who were on scene quickly to help," Boyce said.
"The safety of our students and staff is our top priority, and providing safe and caring environments starts the moment those children board our buses in the morning. We would also like to thank those helpers on the scene who stopped during their morning commute to assist."
Parkland School Division's trauma response team will provide support for the students and their families involved, and staff and classmates if they need it, the news release said.
Parkland RCMP are still on scene with a collision analyst team.
Drivers are asked to find alternate routes around the area for the next few hours while the scene is under investigation.