A woman who was fatally hit Tuesday night on West Avenue in the Roseland area of Santa Rosa has been identified as Amber Smith, 46, of Santa Rosa, the CHP said.

Authorities said Smith had been walking on the sidewalk in dark clothing but then walked into the street and was lying in the center of the northbound lane for unknown reasons when she was struck by a northbound Ford Expedition around 8 p.m.

Smith was treated at the scene and taken to Santa Rosa Memorial Hospital, where she was pronounced dead, the CHP said. Authorities are investigating whether intoxication played a role.

Witnesses at the scene said the Expedition, driven by Santa Rosa resident Maria Martinez, 25, appeared to be traveling at about the speed limit of 25 mph, authorities said.

Smith's companion said they had been looking for her dog, a Chihuahua, when she went into the road near Bayer Neighborhood Park and Gardens and Sheppard Accelerated Elementary School.