Police say Samuel Sidberry got into his car when another student, 16-year-old Joseph Ostrowski, got on top of the trunk of the car.
Ostrowski was injured when he fell off the car and hit his head. The teen was taken to Duke University Hospital with critical injuries.
"It was an accident," Riverside junior Caitlyn Jolly said. "He was sitting on the back of Sam's car and he drove off."
"It was just an accident, and the guy just got on the back and things turned bad," Riverside senior Aaron Fuller said.
On Thursday, news about the accident traveled quickly and word about the severity of Ostrowski's injuries.
"Everybody at school has been all worried about him you know, so I hope he gets better," Riverside junior CJ Wolfe said.
"In one class actually, someone started crying and that's when it started to hit," Fuller said.
Classmates say Ostrowski is a right tackle on the varsity football team at the school. They say all of his teammates are worried about him and his classmates say he was an exceptional student.
"It's really shocking because I mean he's really sweet, like he's been in all my honor's classes since freshman year or so," Jolly said. "Joey, I love you bud ... get better."
Authorities say the accident is still under investigation and no charges have been filed at this time.