Camden's Jesus Diaz, 5, was pronounced dead at the scene of the Route 55 incident in Vineland on July 7, around 11:30 p.m., authorities said.
Then, on July 11, Carlos Diaz, 6, of Camden, passed away, police said.
The two boys were among five children ejected from the Toyota Sienna driven by a 35-year-old Camden mom, New Jersey State Police said.
The minivan went off the roadway, overturned and ended up back on the highway, where it was hit by another vehicle near mile marker 34.6 in Vineland, authorities previously said.
An 8-year-old boy remains hospitalized while two other children have since been discharged, police said.
The crash remains under investigation and no charges have been filed.
Click here to follow Daily Voice Highland Lakes-Vernon and receive free news updates.