'I love you': 10-year-old boy's final words to his brother before he plunges to his death from 18th floor window

Christian Castano uttered his final heartbreaking words as he clung desperately to the  kitchen window-ledge at his mother's flat.

But he was not strong enough to haul himself to safety and brother Steven, eight, could only helplessly watch as he fell 200 feet to the ground.

Tragic: Christian Castano plunged to his death from an 18th floor window

Christian had been waving to friends when a catch on the window which stopped it opening wider than four inches apparently broke.

Neighbours battled to revive him as he lay at the base of the building in North Kensington, London.

Fall: Christian fell from a window at Whitstable House, in London

But he died in hospital following the fall on Saturday evening.

Family friend Ellie Dunne, 27, said: 'Christian managed to say "I love you, bro" to Steven as he lost his grip."

The schoolboy lived in tower block Whitstable House with his parents  -  believed to be Carla and Alexander  -  and two brothers, Steven, eight, and Andre, 18 months.

Last night his devastated mother said: 'I can't explain how I feel. It's such a waste of life.'

It is believed Christian's grandmother Sheila, 49, watched him fall from a neighbouring block.

Furious neighbours have already claimed that basic repairs were not carried out at the site which led to the tragedy.

Barry Farquhar, 34, said Christian must have leaned against the window which opened wider than it should have done and was left hanging from the 18th floor.

The father of four said: 'It would have been like holding onto a saw. He was calling to his friends down below about going on holiday.

'I then heard people screaming. I spent 10 or 15 minutes trying to resuscitate him.

'The windows are the problem. The locks and maintenance are not satisfactory.

'They open from the bottom. He was leaning on them and they opened enough for him to fall out. A lot of people have discussed the faults with regard to the windows.'

One neighbour claimed Christian's mother alerted the housing association, Kensington and Chelsea tenant management organisation, to the faulty window two years ago.

Tributes: Family, friends and neighbours have left dozens of bouquets of flowers at the scene

'On Sunday, after Christian's death, someone from the council turned up and asked if anyone had problems with the windows,' she said.

'It's disgraceful that it takes a child to fall to his death for anyone to bother.'

A housing association spokesman said: 'This is a terrible tragedy and we will be investigating.

'Since the beginning of the year we had only been notified of two minor problems with the windows, neither of which concerned the width restrictors and both were repaired promptly.'