Firefighters rescued 11 people from a fire in a block of flats on Hill Street in Mayfair.
A smoke alarm alerted the residents of the affected flat to the fire.
Station Manager Brett Loft, who was at the scene, said:
“This was a very dynamic incident and firefighters worked fast to rescue 11 people from the block of flats. Seven residents were rescued from the roof level via an aerial appliances as it was the quickest way to bring them to safety. One man was rescued by ladder from a first floor window and three further adults were led to safety via an internal staircase.
“Firefighters managed to contain the fire to a first floor flat, greatly limiting the impact of the blaze on the surrounding properties.
“Thankfully the property had a working smoke alarm which awoke the occupants. Homes need multiple smoke alarms or you won't be properly covered. As a minimum, you should have smoke alarms on every floor of your home - in the hallways and the rooms you use the most plus a heat alarm in the bathroom and kitchen."
Around half of a first floor flat was damaged by fire. Three men and one woman were taken to hospital by London Ambulance Service crews.
The Brigade was called at 0537 and the fire was under control at 0659. Six fire engines and around 40 firefighters from Soho, Paddington, Chelsea and Kensington fire station attended the scene.
The cause of the fire is under investigation.