A neighbour thought at first that Anthony Volney was throwing a bag of rubbish over the balcony. But, the court was told, it was his granddaughter Sasha Davies, who received terrible injuries and died after spending three days unconscious in hospital.
Sasha, 12 days from her fourth birthday, was meant to have been looked after by Mr Volney on the evening of the alleged murder. She was taken to a club near his home in Kilburn, north-west London, where he had caused trouble after drinking and had been asked to leave.
When police forced their way into his flat after the body was found, Mr Volney, 59, allegedly said: "Oh no, what have I done to her. I should be dead."
He was too drunk to be interviewed that night, but claimed the following day that the girl must have wandered off and fallen from the balcony as he slept.
Dorian Lovell-Plank, QC, for prosecution, told the court that Sasha had been taken to the flat by her mother, Nadia Davies, and Mr Volney had offered to look after her.
The girl had spent the night with him before and she was happy with the arrangement. At the time he seemed his normal, happy self, said Ms Davies.
Sasha was later taken by her mother and grandfather to a local club, and Ms Davies left her there with him. He was thrown out later and took Sasha with him, dragging her towards his flat. "She was screaming `I want to go home', and he was saying `you little s***'," said Mr Lovell- Plank.
A woman living opposite the block of flats heard Sasha crying in "a pitiful way", said Mr Lovell-Plank.
"She saw him push the girl so violently that her head collided with a wall of the building. She could hear the impact some 40 yards away."
One of Mr Volney's neighbours described what he saw and heard once Sasha was taken back to the flat.
Mr Lovell-Plank said: "He heard a child in distress and a man who was swearing a lot. He thought the girl sounded petrified. Every time she said something, the man would swear back and she would scream even more. There was one last scream, then he saw the defendant pick up the girl with both hands and drop her over the balcony."
However, Mr Lovell-Plank said, it was dark and at first he thought it may have been a bag of rubbish.
Mr Lovell-Plank told the jury: "The killing of small children is always upsetting. It makes us angry and can make us emotional. Try if you can to put such feelings to one side."
Mr Volney, of Kilburn, north-west London denies murdering Sasha Davies on 6 August last year.
The case continues.