Fifty people face spending the night away from their homes after a fire ripped through five stories of a tower block.
Firefighters tackled the blaze at Shepherd's Court in Shepherd's Bush Green, west London, on Friday afternoon after receiving 40 emergency calls.
Smoke could be seen across the area while videos posted on social media showed flames billowing out of a seventh floor window.
Twenty fire engines and 120 firefighters attended the scene and evacuated the whole building.
One woman was treated for smoke inhalation and shock, but London Fire Brigade (LFB) said there were no other reports on injuries or unaccounted persons.
The fire affected five floors in the 18-story block of flats.
Station manager, Paul Hobbs, who was at the scene, said: "The fire spread from the seventh floor via the outside of the building. Crews wearing breathing apparatus used jets to extinguish the fire on each floor of the building. They worked quickly in difficult conditions to tackle the fire."
Witness Helena Noifield told BBC Radio London: "Everyone's standing around not knowing where to go.
"It's all pretty horrible really. There's ash everywhere, smoke everywhere... it's like something out of a horror film. It's ghastly."
The fire was under control by 5.32pm but crews remained at the scene on Friday evening damping down.
The brigade said that the cause of fire was under investigation.