Pictures from Chopper 11 HD showed their 1996 Chevy Camaro rolled several times near the intersection of Marks Creek, just north of U.S. 64 near Knightdale.
Eyewitness Neil Hunter says he heard the car coming and moments later saw it veering off the road.
"I heard like the engine revving, you could tell that they were getting on it, like coming right there," Hunter said. "I saw them get sideways and then right there, you can see they hit and then they flipped."
Authorities say the driver, 17-year-old Austin Marx, was speeding on Puryear Road when he lost control of the car, causing it to flip several times. Marx and his passenger, 16-year-old Gavin Westover, suffered serious injuries.
"The driver was actually like yelling, and the passenger, like 'help,'" Hunter said.
"We couldn't move them," said Jeff Beck, who arrived on the scene after accident. "We couldn't open the doors. They had to bring a saw out and try and get them out."
The teens were taken to WakeMed. Officials say both were wearing seat belts.
The state patrol says Westover remains in very critical condition at the hospital, while it appears Marx has been treated and released. Details about their injuries are not available at this time.
Those familiar with the road say accidents are common there.
"Stuff like this always happens out here," Hunter said. "I just didn't expect it to be like that severe, because usually people like flip and they just get out. We've had people like flip and land right there in that yard. We've had people over there up there. It happens like twice a year."