It happened around 5:00 Saturday afternoon near East 11th and Upland streets.
Officials say a van struck 4-year-old Karder Hardy after he apparently bolted out of his mother's grip and ran into the street.
"He was handsome. He would run around and bounce off the walls," said Denise Brown, great-aunt.
The driver of the striking vehicle remained at the scene. The 42-year-old male, who was driving a company truck for a South Jersey business, was taken in for questioning by police.
"Apparently this is being investigated as a tragic accident," said Chief Joseph Bail, Chester Police.
"I was coming down the street when he got hit. I saw him on the ground and I was holding him and telling him to hold on, but I think he was already dead," said Brown.
Mayor John Linder arrived at the scene moments after the tragedy trying to comfort the grieving family.
"I do know the family. I am familiar with some of the members and the grandmother. You can't explain it, no one wants to go through that - to bury your son and then your grandson dies the same day, said Mayor Linder.
Derrick Brown, the child's father, was a prominent business man in town and owned a barbershop.
He was murdered last Saturday night. Police he was an innocent bystander who was hit by bullets intended for a 16-year-old pedestrian.
"Any child struck is a tragedy but for this family this is just a compound tragedy," said Chief Bail.
"To have a child, in any capacity, die is overwhelming. It's doubly overwhelming for the family. We're just trying to embrace the family, support them as much we can, bring in every support we can to bear with them and help them get through this," said Mayor Linder.
The victim's family is still in shock and now they are preparing yet another funeral.
