A three-year-old boy died in hospital after being found in a garden pond during a visit to relatives.
The child was discovered in the rear garden of a house in Moseley, Birmingham.
Neighbours said the boy had been visiting his aunt and uncle at a property nearby when he went missing while playing with his cousins.
Dozens of police officers and a helicopter joined in the search to find the youngster before he was discovered in the garden of a house on Anderton Park Road. He had been reported missing to police around an hour earlier.
The boy was rushed to Birmingham Children's Hospital but died shortly before midnight, West Midlands Police said.
A force spokesman said: "We can confirm that sadly he has died. West Midlands Police sends its sincere condolences to his family. It was a tragic accident. It is not been treated as suspicious at this stage. A post-mortem will take place in due course."
The little boy is believed to have been playing in the garden of his relatives' large detached home on Coppice Road, which backs onto the property on Anderton Park Road.
The owners of the Coppice Road house did not want to comment.
Their neighbour, a 67-year-old man, said he understood the boy had been playing with his cousins when he disappeared.
He said: "The children were playing when he apparently got lost. He does not live on this street - he was visiting the house with his parents. He must have got through the gardens."
