IMPERIAL BEACH–A bicyclist riding on an Imperial Beach road was struck by an oncoming vehicle on Saturday, authorities say.

Sheriff’s deputies said the collision occurred at 4th Street and Palm Avenue.

Three adults were riding bicycles in the bicycle lane of eastbound Palm Avenue. As they crossed 4th Street, one of the adult riders, a 57-year-old adult female, was struck by a vehicle turning left  from Palm Avenue to 4th Street. The driver of the vehicle remained at the scene and is cooperating with the collision investigation.

Paramedics transported the female to an area hospital for treatment of serious injuries.

A preliminary investigation has determined alcohol and drugs are not a factor, and the investigation is still ongoing.