A baby boy is in a stable condition after a crash left his mother dead while a man is the third death on Victoria's roads in 24 hours.
The woman was killed after her car came off Geelong-Bacchus Marsh Road in Balliang East, west of Melbourne, shortly after 2.15pm on Friday.
"You've got a young mum weeks out from Christmas with her young child in the car, who has lost her life through no fault of her own," Major Crash Unit investigator Philip Frith told reporters at the scene on Friday.
The baby boy survived the crash with minor injuries and was rushed to the Royal Children's Hospital in Melbourne.
He remains in a stable condition in hospital, a spokeswoman confirmed on Saturday.
A B-double truck heading in the opposite direction may have flicked up debris from the road into the car, causing the vehicle to veer off the road and hit a tree, investigators believe.
It comes after a male driver died after his Nissan Patrol SUV crashed into the rear of a truck at Campbellfield, in Melbourne's north before 6.15am on Saturday.
Another man, aged in his 60s, died in a crash on Forrest-Apollo Bay Road, on Friday.
The latest death brings the state's road toll to 256.
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