Fire has engulfed Grenfell Tower, on a housing estate near White City shopping centre.
Police say a number of people are being treated for various injuries and hundreds of people are being evacuated from the 27-storey building
The fire broke out just after 1am and witnesses say there is very little of the building remaining.
Police say the A4 is closed in both directions because of the fire.
A police officers tells the crowd that they need to stay behind the line – “the less police officers we have here, the more we can help people”, he says:
At least 200 firefighters have been battling the difficult blaze, many for more than four hours now.
London Ambulance Service sent more than 20 ambulance crews as well as its hazardous area response team.
Witness says he can see someone inside the building, in the area that seems to be unaffected. He is surrounded by flames but “seems quite calm, is pacing up and down inside, walking towards the window drinking a glass of water”.
The hope is emergency services know where he is and can get to him quickly.
And this is what the fire looks like from above: