EVERETT, Wash. -

Snohomish County sheriff's detectives say a young girl who disappeared several years ago died under mysterious circumstances -- and they believe they've found her remains encased in concrete inside a plastic storage bin.
   
The Daily Herald newspaper of Everett reported the investigation began when a relative left a voicemail for police in October, though Child Protective Services workers had also been trying to find her.
   
Relatives told investigators they believed the girl died about four years ago, when she was about 4 years old. They said her mother and stepfather told varying stories about what happened to her, including that she had gone to live with other relatives, that she had died of chickenpox and that she had drowned while taking a bath.
   
No arrests have been made, nor has the coroner confirmed the identity of the remains. The sheriff's office says it continues investigating.