Around 120 people were evacuated as dozens of firefighters tackled a fire in a 17-storey block of flats in southeast London.
A flat on the 15th floor of the tower in St Mark's Square, Bromley caught alight as well as part of the roof, the London Fire Brigade (LFB) said.
No injuries have been reported and the cause of the blaze is unknown.
It has since been brought under control - but fire crews will remain on scene damping down for several hours to come.
Footage posted on social media showed flames and black smoke coming from one part of a slanted roof.
As the blaze was ongoing, Station Commander Colin Digby, said: "Crews are making steady progress. This is going to be a protracted incident and we expect our crews to be on scene for several hours to come."
Around 100 firefighters tackled the fire after emergency services were called just before midday.
Fire crews used a 64-metre turntable ladder to assist them.
Teams from Bromley, Beckenham, Addington, Woodside, Lewisham, Forest Hill, Sidcup and Croydon and surrounding fire stations were involved in the response.
Josh Gill, 29, a Co-op team leader from Bromley, said: "I literally live on the doorstep.
"I was in my flat and my mother-in-law came over to pick up my wife's niece who stayed over last night, and as she came she said about the fire and saw all the fire brigade appear and (I) went to have a look.
"Some people were upset and crying whilst others were shocked and confused as to what was going on. The fire brigade are still here and you can see people who live in the flats evacuated in the church."
"It is scary to see this right on the doorstep as I have a family."