Ontario Provincial Police said a tractor-trailer and a van collided near the turnoff to Highway 416 at about 1 a.m. ET Monday.
Pronounced dead at the scene were the three of the van occupants, all from Chateauguay, Que.:
- Elissa Reid, 22.
- Moriah Gloria Warren, Reid's two-month-old daughter.
- Sheila McGlashen, 78, Reid's grandmother.
Three other family members in the van — Reid's father, mother and brother — were transported to Winchester Hospital and subsequently to the Civic Hospital in Ottawa with serious but non-life-threatening injuries.
The driver of the tractor-trailer was treated at Cornwall Community Hospital for minor injuries and has since been released.
Police said a fire erupted in the tractor-trailer after the collision and spread to the van.
It took crews several hours to remove the tractor-trailer from the scene.
Highway 401 westbound lanes opened to traffic at 9:30 a.m. One lane of Highway 401 eastbound remains closed.
Ontario Provincial Police officers remain at the scene and continue to investigate.