OPP officials have identified the driver and passenger killed in yesterday's crash on the QEW near Burlington.
The driver has been identified as Ceara Publuske of Kitchener and the passenger was Courtney Duguay of Owen Sound.
The crash happened around 5:30 a.m. when a westbound Mitsubishi crossed into the eastbound lanes and hit an Acura.
The Mitsubishi was then hit by a truck and a fourth vehicle lost control, rolling into the centre ditch.
Both women in the Mitsubishi were killed and three other people were taken to hospital with non-life threatening injuries.
The lanes of the QEW were closed for several hours.
The investigation into the cause of the crash is ongoing.