Seattle Police detectives are investigating after an accident early Monday morning just south of the Ballard Bridge left one woman dead.

According to police, shortly after 1 a.m. Monday, officers found an unconscious woman trapped inside a Toyota Matrix at the intersection of 15th Avenue West and West Emerson Street. A passerby had called 911, having spotted the vehicle after it had apparently crashed into a guardrail.

Despite life-saving efforts from Seattle Fire Department medics, first responders declared her dead at the scene.

Investigators are now working to determine what led up to the accident. Witnesses are asked to call the Traffic Collision unit at 206-684-8923 to speak with an officer.