A 48-year-old Bolinas woman was killed and her 7-year-old son injured Wednesday night after her car veered from Highway 1 near Bolinas and struck a tree.

Barbara Rothwell was declared dead at the scene by county paramedics after her son climbed from the wreckage to summon help.

California Highway Patrol spokesman Eric Hoh-meister said the black BMW traveling south swerved from the roadway at about 8:15 p.m. about a half-mile north of Olema-Bolinas Road, traveled 15 feet down an embankment and hit a tree.

Rothwell was pinned inside the car. Authorities were alerted when the youngster climbed out to seek help.

"The young child went to a nearby home and said they'd been in an accident and his mom needed help," said Bolinas fire Chief Anita Tyrell-Brown.

Bolinas firefighters cut the roof from the car and pulled Rothwell from the wreckage.

Eight Bolinas firefighters, most of them volunteers, responded on Engine 285 and Rescue Unit 219, assisted by fire crews from Stinson Beach and Point Reyes.

The child was treated for minor injuries.

Rothwell was identified as the victim Thursday morning by sheriff's Lt. Keith Boyd, who serves as the county's assistant chief deputy coroner.

An investigation into the cause of the accident is continuing.