The accident happened just before ten last night on Avenue 7 and Road 29 in Madera County.
Investigators say the driver of a white Cadillac, 32-year-old George Gonzalez Jr. of Fresno ran a stop sign and hit a car carrying five people.
"The vehicle broadsided a Honda Accord. Both vehicles left he roadway. One of them overturned. As a result of the collision a passenger in the Honda was ejected from the vehicle," Sgt. Michael Donnelly of the California Highway Patrol said.
The 22- year old woman who was ejected from the Honda died at the scene. A one-month old baby boy died at the hospital Monday morning.
A two-year old girl and a man in the Honda were also injured. They were taken to community regional medical center for treatment.