A boy aged 21 months fell 150ft to his death from a tower block after his parents put him in his cot by an open window 'during a drinking session'.
Alexander and Taisiya Akimov, from Russian capital Moscow, found out their son Timofei had been killed when police rang their doorbell to say his body had been found after his fall.
He had climbed out of a 14th floor tower block window, say law enforcement.
The parents, aged 21 and 23, were detained on suspicion of causing death by negligence.
Investigators said there was evidence they had been drinking when their son climbed from his cot out of the open window.
The tragic case prompted the Russian Investigative Committee - which probes serious crimes - to warn parents about the risk to children in high-rise buildings.
This was the third such case in one day, said reports.
It came in a week when Vladimir Putin's children's ombudswoman Anna Kuznetsova revealed that 145 children died last year from 1,339 cases when they had fallen from open windows.
