An 8-year-old boy riding a bicycle on the northwest side was struck in a hit-and-run Thursday.

The boy, who was wearing a helmet and was in a crosswalk, was in serious but stable condition at University of Arizona Medical Center, said Capt. Adam Goldberg, a Northwest Fire District spokesman.

The boy's injuries are non-life threatening. "His injuries were reduced because he was wearing a helmet, and that helped save his life," Goldberg said.

Paramedics were dispatched at 6:17 p.m. to the hit-and-run on West Curtis Road at North Shannon Road, said Goldberg. 

Deputies of the Pima County Sheriff's Department closed the area to traffic while they investigate.   

The vehicle that struck the boy fled the scene, said Goldberg.

Investigators do not have a description of the vehicle, said Deputy Courtney Rodriguez, a sheriff's department spokeswoman.

Anyone with information is asked to call 911 or 88-CRIME.