"It was very shocking [and] really unexpected," witness Marin Boieru told Eyewitness News.
Boieru said he heard a crash and then saw the child's body fly through the air, hit the ground and roll over once or twice.
The Cary Police Department said 6th grader Joseph Liptak was crossing the street to get on the bus when he was hit.
Police say a red pickup truck that was traveling on Penny Road failed to stop behind the school bus' stop arm and struck the boy.
"They [the pickup truck driver] got out and run toward the child," Boieru explained. He said the driver seemed concerned.
But Boieru said he was angered by what he had witnessed. "I opened the door and was so angry and screamed, 'Why didn't you stop?'"
Chopper 11 was over the scene as the boy was put on a stretcher and taken to WakeMed.
Boieru said he was taking his own daughter to school when everything happened. His daughter also witnessed the collision and was too distraught to go to school.
School officials say this should serve as a wake up call to all drivers.
"When that stop arm comes out, there's a reason and drivers cannot take things into their own hands and decide to try and pass because it could have been much more serious," said Michael Evans, Wake County Schools.
Evans said Liptak was alert and responsive, but complained of aches and pains. The driver of the truck, 50-year-old Rita Braman, was also taken to the hospital.
Wake County Schools told Eyewitness News Oak Grove Elementary is a hub for students who are transported to other schools.
"It could have been one of my daughters," Boieru said.
Liptak was rushed to the hospital after the truck hit him, he is still recovering at Wake Med.
Braman is charged with failing to stop for a school bus.