EUGENE, Ore. -- Lane County sheriff's deputies are investigating the drowning of a 3-year-old girl in Fern Ridge reservoir west of Eugene.

Deputies believe the Sunday death of Trinity Gullum, who would have been 4 on August 18, was accidental. But many questions are unanswered.

Investigators said the girl was wearing a life jacket and an inflatable tube around her waist when she wandered alone to water about a foot deep.

Relatives say they took their eyes off the girl only briefly before they heard screams and saw her face-down in the water.