Ontario Provincial Police say one man has been arrested after a crash on the 401 near Cornwall.
The collision happened at around 4:15 p.m. Tuesday, between McConnell Avenue and Boundary Road.
Police say a U-Haul traveling west entered the eastbound lanes and hit a car.
The reason why the commercial vehicle swerved into oncoming traffic remains under investigation, police say.
The driver of the car was seriously hurt and rushed to hospital. The other driver was not hurt, but is now in police custody.
There is no word yet on charges.
Eastbound lanes remain closed at this time.