Photo by Alexander Nguyen

A 19-year-old pedestrian was seriously injured Wednesday in a hit-and-run on an eastern San Diego County roadway, authorities reported.

The young woman was walking to the south along the western edge of South Grade Road near Manzanita View Road in Alpine when an unknown type of vehicle struck her from behind about 11:15 a.m., according to the California Highway Patrol.

After the pedestrian was hit, the unidentified motorist continued driving and left the area to the south, CHP public-affairs Officer Travis Garrow said.

Paramedics airlifted the victim to Sharp Memorial Hospital in San Diego for treatment of severe injuries.

Anyone who might be able to help identify the hit-and-run driver is asked to call the CHP at 619-401-2000.