SAN MARCOS ---- A motorist struck a girl and her dog in San Marcos on Monday morning, injuring the pedestrian and killing her pet, authorities said.

The driver of a 2008 Jeep Cherokee remained at the scene after hitting the 15-year-old girl walking her dog on Dove Tail Drive about 6:30 a.m. Monday, said San Diego County sheriff's Lt. Hope Andrews.

Bruce Coleman, 45, a neighbor, said he saw the San Marcos High sophomore lying in the bike lane, stopped his car, jumped out, and told his daughter to call 911. He also saw a pug bleeding in a planter and an iPod on the road.

Moments later, he saw a woman in her late twenties run to the scene in hysterics. Coleman said he talked with the teenager to try to keep her awake and alert until paramedics arrived.

Children's Hospital officials confirmed that the girl was taken to the emergency room on Monday, but said she was not admitted. They declined to comment further.

A family member of the girl reached Tuesday also declined to comment on her condition.