Janesville police are still piecing together the details of what happened yesterday.
Emergency workers were called to a home on the city's west side around 5:40 last night for an accidental drowning.
Lydia Sears was in a neighbor's aboveground pool. The neighbors apparently weren't home at the time, but the pool was surrounded by a chain-link fence with locked gates.
Police say Lydia was taken to a Madison hospital, where she was pronounced dead.
They aren't sure how the little girl got into the pool.