A collision has left a semi-truck flipped over, with its trailer detached and fuel leaking, at the Highway 2 and 338 Avenue intersection near Okotoks.
Traffic is being diverted on Highway 2 southbound. Northbound traffic is down to one lane.
Okotoks RCMP is asking drivers to avoid the area and seek alternate routes or experience major delays.
The mutli-vehicle collision was reported at approximately 1:45 p.m.
One person has been airlifted to hospital with life-threatening injuries, an EMS spokesperson said.
A second person was taken to hospital by ground ambulance with non-life-threatening condition.
EMS vehicles, fire engines, RCMP and STARS were dispatched.
Vac trucks are on scene assisting with the clean up of fuel from the semi-trailer.