On Wednesday night around 6:26 p.m, a driver on the interstate saw a fire in the greenbelt just east of I-5 and called 911.
Seattle Fire Department responded to the Mountain to Sound trail and began working to put out the blaze. While clearing the area, firefighters located possible human remains.
Detectives with the Homicide Unit will be conducting the follow-up investigation.
Anyone with information is asked to call the Seattle Police Department Violent Crimes Tip Line at (206)233-5000.