CUPERTINO, Calif. (KGO) -- A teenager was killed Monday morning while riding his bike to school in Cupertino. The truck driver who struck him had to be flagged down by witnesses.



The accident happened as the teen, who was on a bike, and a gravel truck were both traveling westbound on McClellan Road, which has a bike lane. Investigators are still trying to determine where the cyclist was when he was struck.



Multiple witnesses saw the accident. "The driver of the truck continued on, not knowing he had struck the teenage boy. Witnesses were able to successfully flag him down and notify him he'd been involved in an accident. He stopped and has been cooperative with us," said Sgt. Kurtis Stenderup, with the Santa Clara County Sheriff's Department.



The truck is registered to a Tracy company, Moonlight Express. The driver has been interviewed by investigators but not cited. While no blame has been established, some cyclists worry that teens not yet of driving age may not be aware of the hazards of sharing the road.



"You don't understand how dangerous cars are and the power that they have and how vulnerable you are as a cyclist. So the kids under 16, I don't think really get it," explained cyclist Margaret Koniniec.



Shreya Swaminath, a student from nearby Monta Vista High School, says her perspective changed when she got her license. "I got my license like a year ago, so I understand for drivers, it's really hard to see where bikers, are and bikers are kind of reckless, like watching where they are in comparison to the car. And they don't follow the white line. You have to be very careful," she said.



The identity of the cyclist is being withheld until family has been notified. That has led to a day of uncertainty at Monta Vista High School.



"There's not a lot of information that kids know, so it's a lot of 'I don't knows.' People are just worried," said student Jarrett James.



School administrators say they will be prepared to offer counseling once there is confirmation the student was one of their own.



Meanwhile, McClellan Road in Cupertino is now open after being closed for the police investigation.