A man in his 90s is in life-threatening condition, Orillia OPP say, following a collision on Highway 12 near Concession Road 11 in Ramara Township.
Police say the incident happened on Tuesday just before 7 p.m.
"The initial information was that two vehicles had collided, one was in the ditch on fire, the other vehicle was still in the roadway, with occupants trapped inside," OPP said in a release.
"With the assistance of Rama Police Service, Simcoe County Paramedics and Ramara Fire, everyone was able to get occupants out of the vehicle. Two parties were transported to a local area hospital."
They say the man in his 90s was airlifted to a Toronto area trauma centre with serious injuries.
The highway was closed for investigators but has since been re-opened.
OPP continue to investigate and ask anyone who witnessed the crash or has camera footage to contact them at 1-888-310-1122.