Six people were sent to hospital following a major pileup on Highway 401 just east of Port Hope on Thursday night.
Around 9 p.m., emergency services responded to the multi-vehicle collision in the eastbound lanes near the Hamilton Township overpass following reports a tractor-trailer collided with several vehicles.
Two vehicles were found on the highway while a van and a transport truck were in a ditch, all with significant damage.
Paramedics say four people in one van, a person in another van and one person in a car were all transported to Northumberland Hills Hospital in Cobourg with injuries ranging from minor to critical.
Northumberland OPP on Friday morning said one of the victims – a 55-year-old woman – was airlifted to a Toronto-area hospital with serious injuries.
The transport driver was not injured.
The highway’s eastbound lanes were closed all night and reopened around 7:20 a.m. Friday.
The Ministry of the Environment also attended the scene to address a diesel fuel leak.
OPP continue to investigate the cause of the collision.
WATCH: Transport collides with vehicles on Highway 401 near Grafton