A skateboarder suffered major injuries in a collision with a vehicle Sunday in Livermore, police said.
Officers responded at about 7 p.m. to a collision on Portola Avenue at North L Street.
Police said the collision involved a skateboarder and a 1997 Toyota Avalon.
When officers arrived, they found an 18-year-old Livermore man unconscious in the road after being struck by the Toyota.
Police said the skateboarder was not wearing a helmet when the Toyota hit him.
Police said it appears that the Toyota was traveling west on Portola Avenue when the Livermore man entered the road riding the skateboard.
The skateboarder was taken to a hospital while the driver of the Toyota escaped injury.
Police said while the collision is under investigation, neither drugs nor alcohol nor speed appears to have played a part in the collision.
Investigators are asking anyone with more information to call Livermore police Officer Pini at (925) 371-4896.