Sleeping residents were evacuated from a tower block and 16 people taken to hospital after a fire in a third-floor flat.
Firefighters rescued 50 people from the 14-storey building in west London and two residents were forced to escape from their balconies as the blaze raged.
Residents crawled to safety and described seeing "fireballs" at Adair Tower in Appleford Road in North Kensington.
London Fire Service arrived just before 9am, with many residents still asleep.
Nanga Pedro, 34, lives opposite the blaze-hit flat with his wife and two young children.
He said: "I was sleeping and my wife was getting ready to go out. As she went to leave she saw the smoke everywhere and woke us all up. We tried to leave but it was impossible.
"We couldn't wait for them (the firefighters) so we crawled. We all crawled through the lobby under the smoke."
Around 60 firefighters and eight fire engines rushed to the block of flats after the blaze broke out in a studio apartment.
They rescued 50 people, including two stuck on a balcony, and evacuated the building. Sixteen people were taken to hospital as a precaution, the fire service said.
Residents living in the tower block said flat number 15 had initially caught fire.
Mashuoul Islam, 57, lives in the property which adjoins the blaze-hit apartment.
He first realised something was wrong when his 13-year-old son smelt smoke and noticed the top of his wall - which adjoins the burned property - had turned black.
He said: "It was very scary. It was so black, there was so much smoke and some little fireballs. We were stuck for a few minutes but then they came and escorted us out."
Mr Islam was told he would not be able to return to his flat today.
He said: "We haven't got anywhere to go, we haven't got anything to eat, we haven't got anywhere to sleep. We don't know what to do."
A nearby church, Our Lady of the Holy Souls, opened for residents, offering tea and coffee.
Fire crews had the blaze under control after just over an hour although 12 flats were deemed "uninhabitable" by the council.
The council has advised affected residents to spend the night with relatives living close by or alternatively they will be put up in a bed and breakfast.
Yasmin Akhtar lives on the second floor and described seeing "large flames" after she was rescued.
She said: "I was sleeping and a woman started shouting 'Wake up, there's a fire' but I thought she was joking."
"Then firefighters came to the door. I woke up my son. He had to come out in his pyjamas."
Station manager Jim Smith, who was at the scene, said a third-floor flat was "completely alight and smoke was pouring from a window" when fire crews arrived.
He added: "Control officers did a brilliant job keeping residents calm and ensuring those who were trapped or couldn't move were in the safest place while firefighters reached them."
Police and fire crews were investigating the cause of the fire, which destroyed the apartment and damaged neighbouring flats.
The Metropolitan Police said no arrests had been made.
Fire service control operations manager Liz Hymns said: "Our job is to keep people calm and make sure they are in the safest possible place.
"We took nine fire survival calls during this incident, we gave residents reassurance and made sure they were in the safest place.
"For example, in one call, a woman couldn't move from the back bedroom but we got her to describe the layout of her flat so that when firefighters arrived they knew exactly how to find her.
"Obviously, when you speak to people in this situation they are scared and looking for reassurance. It's the most amazing feeling in the world to hear the relief in their voices when they hear firefighters breaking into their flat and they know they are going to be rescued."